2002–2006: Breakthrough

In 2002, she was the singles champion of both the Belgium and Frankfurt International Championships and a finalist at the Orange Bowl. In June 2003, she captured the prestigious French Open junior title, becoming the first player from Germany since 1957 to accomplish this feat. In July 2003, she continued her superb form and won the Apple and Eve Newsday Long Island Classic, held in Woodbury, New York. She was also an accomplished doubles player in juniors winning the French Open title and reaching the finals at Wimbledon. As a result of her tennis success in 2003, Grönefeld had achieved the junior world ranking of No. 1 in singles and doubles. She launched her professional career debut under the direction of the USA Academy and Rafael Font de Mora.

Grönefeld made her professional breakthrough in 2005, rising 54 places throughout the year. She reached the third round of the Australian Open, French Open and the US Open and played three finals in WTA Tour events throughout the season, including at the Tier II event in Beijing, although failing to win any of them. She also rose into the top 10 in the world in doubles, cementing her position as one of the most promising young doubles players on the tour at the time.

In 2006, she represented Germany along with Nicolas Kiefer at the Hopman Cup. She went on to win her first title at the Mexican Open in Acapulco and completed a career best showing at Roland Garros, by reaching the quarterfinals, where she lost to Justine Henin. Her ranking peaked at 14, and remained in the top 20 for much of the year, despite a significant drop in results in the latter half of the season, as the German failed to progress beyond the quarterfinals of most tournaments. She split with Font de Mora in September 2006 and began to work with Dirk Dier.

2007: Loss of form

Her run of bad form continued into 2007, and as of 19 June, Grönefeld had been eliminated in the first round of her last five tournaments. Grönefeld blamed her run of bad form on the situation with Font de Mora, suggesting that he was giving her opponents tactics on how to beat her. She also had a substantial weight gain over the past several months.^[4] Her ranking subsequently dipped below the top 100 for the first time since 2004. On 20 August 2007, Grönefeld announced that she would be taking a break from the tour, coming back in 2008.

In August 2007, it was revealed that Font de Mora was planning to sue Grönefeld for lack of discipline during their partnership, stating: "She had to adhere to a standard of performance, a standard of training and a standard of diet. She absolutely let herself go and sabotaged her marketability and her performance on the court. You work for years and invest all this money into developing contracts and developing endorsements and then she just gets around the wrong people and does the wrong things and her performance affects everything."^[5] He also denied her allegations that he interfered with her matches.

2008–2009: Comeback

Grönefeld made her official comeback on 3 May 2008, at the $75,000 ITF event in Zagreb, Croatia. She was seeded 4th in the qualifying draw, winning three consecutive matches to reach the main draw. She then won the Smart Card Open Monet+ in Zlín, Czech Republic, for the first title of her comeback. Grönefeld went on to win another two ITF title over the following fortnight: a $10,000 event in Alkmaar, Netherlands, and a $25,000 event at Périgueux, France.

Grönefeld took advantage of her feed-up wildcard into the Tier IV Gaz de France Grand Prix (a result of winning the $75,000 Zlín ITF event), reaching the quarterfinals with an upset win over Lucie Šafářová. She then played in Bad Gastein, where she was defeated in three tight sets in the second round by Pauline Parmentier.

Her good form allowed Grönefeld to win another $50,000 ITF event in Rimini at the beginning of August. She also reached the final of a $50,000 event in The Bronx, where she lost to Elena Bovina.

After winning her three qualification rounds, Grönefeld played at the 2008 US Open, and reached the fourth round of the main draw, only losing to Dinara Safina. Prior to her loss to Safina, Grönefeld had won six matches in a row without losing a single set, the highlights being her victory over Daniela Hantuchová in the first round and over Alizé Cornet in the third round, both top 20 players at the time.

After losing against Austrian runner-up Tamira Paszek in the first round in Bali, Grönefeld received a wildcard for the Porsche Tennis Grand Prix in Stuttgart but lost in the first round against Venus Williams. With her doubles partner, Patty Schnyder, Grönefeld, however, won the doubles competition against the top seeds Květa Peschke and Rennae Stubbs.

After winning the first two matches at the qualification for the Zurich Open, Grönefeld lost her third match against Petra Kvitová. With doubles partner Patty Schnyder she reached the finals.

Singles

Doubles

Mixed doubles

Grand Slam finals

Mixed doubles: 4 (2 titles, 2 runner-ups)

Result	Year	Tournament	Surface	Partner	Opponents	Score
Win	2009	Wimbledon	Grass	Mark Knowles	Leander Paes Cara Black	7–5, 6–3
Win	2014	French Open	Clay	Jean-Julien Rojer	Julia Görges Nenad Zimonjić	4–6, 6–2, [10–7]
Loss	2016	Wimbledon	Grass	Robert Farah	Henri Kontinen Heather Watson	6–7(5–7), 4–6
Loss	2017	French Open	Clay	Robert Farah	Gabriela Dabrowski Rohan Bopanna	6–2, 2–6, [10–12]

Premier Mandatory / Premier 5 finals

Doubles: 10 (1 title, 9 runner-ups)

Result	Year	Tournament	Surface	Partner	Opponents	Score
Win	2005	Toronto	Hard	Martina Navratilova	Conchita Martínez Virginia Ruano Pascual	5–7, 6–3, 6–4
Loss	2006	San Diego	Hard	Meghann Shaughnessy	Cara Black Rennae Stubbs	2–6, 2–6
Loss	2006	Toronto	Hard	Cara Black	Martina Navratilova Nadia Petrova	1–6, 2–6
Loss	2012	Tokyo	Hard	Květa Peschke	Raquel Kops-Jones Abigail Spears	1–6, 4–6
Loss	2013	Toronto	Hard	Květa Peschke	Jelena Janković Katarina Srebotnik	7–5, 2–6, [6–10]
Loss	2013	Cincinnati	Hard	Květa Peschke	Hsieh Su-wei Peng Shuai	6–2, 3–6, [10–12]
Loss	2017	Toronto	Hard	Květa Peschke	Ekaterina Makarova Elena Vesnina	0–6, 4–6
Loss	2019	Rome	Clay	Demi Schuurs	Victoria Azarenka Ashleigh Barty	6–4, 0–6, [3–10]
Loss	2019	Toronto	Hard	Demi Schuurs	Barbora Krejčíková Kateřina Siniaková	5–7, 0–6
Loss	2019	Cincinnati	Hard	Demi Schuurs	Lucie Hradecká Andreja Klepač	4–6, 1–6

Singles: 4 (1 title, 3 runner-ups)

Result	W–L	Date	Tournament	Tier	Surface	Opponent	Score
Loss	0–1	Feb 2005	ThailandOpen, Pattaya City	Tier IV	Hard	Conchita Martínez	3–6, 6–3, 3–6
Loss	0–2	Sep 2005	China Open, Beijing	Tier II	Hard	Maria Kirilenko	3–6, 4–6
Loss	0–3	Oct 2005	Luxembourg Open, Luxembourg City	Tier II	Hard (i)	Kim Clijsters	2–6, 4–6
Win	1–3	Mar 2006	Mexican Open, Acapulco	Tier III	Clay	Flavia Pennetta	6–1, 4–6, 6–2

Doubles: 44 (17 titles, 27 runner-ups)

Result	W–L	Date	Tournament	Tier	Surface	Partner	Opponents	Score
Loss	0–1	Aug 2004	Nordic Light Open, Stockholm, Sweden	Tier IV	Hard	Emmanuelle Gagliardi	Alicia Molik Barbara Schett	3–6, 3–6
Loss	0–2	Aug 2004	Vancouver Open, Canada	Tier V	Hard	Els Callens	Bethanie Mattek-Sands Abigail Spears	3–6, 3–6
Loss	0–3	Aug 2004	Cincinnati Masters, United States	Tier III	Hard	Emmanuelle Gagliardi	Marlene Weingärtner Jill Craybas	5–7, 6–7(2–7)
Loss	0–4	Oct 2004	Filderstadt Open, Germany	Tier II	Hard (i)	Julia Schruff	Cara Black Rennae Stubbs	3–6, 2–6
Win	1–4	Feb 2005	Thailand Open, Pattaya City	Tier IV	Hard	Marion Bartoli	Marta Domachowska Silvija Talaja	6–3, 6–2
Win	2–4	Aug 2005	Canadian Open, Toronto, Canada	Tier I	Hard	Martina Navratilova	Conchita Martínez Virginia Ruano Pascual	5–7, 6–3, 6–4
Win	3–4	Sep 2005	Bali International, Indonesia	Tier III	Hard	Meghann Shaughnessy	Yan Zi Zheng Jie	6–3, 6–3
Win	4–4	Mar 2006	Mexican Open, Acapulco, Mexico	Tier III	Clay	Meghann Shaughnessy	Shinobu Asagoe Émilie Loit	6–1, 6–3
Win	5–4	Jul 2006	Stanford Classic, United States	Tier II	Hard	Shahar Pe'er	Maria Elena Camerin Gisela Dulko	6–1, 6–4
Loss	5–5	Aug 2006	Southern California Open, San Diego, United States	Tier I	Hard	Meghann Shaughnessy	Cara Black Rennae Stubbs	2–6, 2–6
Loss	5–6	Aug 2006	Canadian Open, Montreal, Canada	Tier I	Hard	Cara Black	Martina Navratilova Nadia Petrova	1–6, 2–6
Loss	5–7	Oct 2006	Luxembourg Open	Tier II	Hard (i)	Liezel Huber	Květa Peschke Francesca Schiavone	6–2, 4–6, 1–6
Win	6–7	Jan 2007	Sydney International, Australia	Tier II	Hard	Meghann Shaughnessy	Marion Bartoli Meilen Tu	6–3, 3–6, 7–6(7–2)
Win	7–7	Oct 2008	Stuttgart Open, Germany	Tier II	Hard (i)	Patty Schnyder	Květa Peschke Rennae Stubbs	6–2, 6–4
Loss	7–8	Oct 2008	Zurich Open, Switzerland	Tier II	Hard (i)	Patty Schnyder	Cara Black Liezel Huber	1–6, 6–7(3–7)
Win	8–8	Nov 2008	Tournoi de Québec, Canada	Tier III	Carpet (i)	Vania King	Jill Craybas Tamarine Tanasugarn	7–6(7–3), 6–4
Win	9–8	Jan 2009	Brisbane International, Australia	International	Hard	Vania King	Klaudia Jans Alicja Rosolska	3–6, 7–5, [10–5]
Win	10–8	Oct 2009	Linz Open, Austria	International	Hard (i)	Katarina Srebotnik	Klaudia Jans Alicja Rosolska	6–1, 6–4
Loss	10–9	Mar 2010	Monterrey Open, Mexico	International	Hard	Vania King	Iveta Benešová Barbora Strýcová	6–3, 4–6, [8–10]
Win	11–9	Aug 2010	Danish Open, Copenhagen, Denmark	International	Hard (i)	Julia Görges	Vitalia Diatchenko Tatiana Poutchek	6–4, 6–4
Loss	11–10	Mar 2011	Monterrey Open, Mexico	International	Hard	Vania King	Iveta Benešová Barbora Strýcová	7–6(10–8), 2–6, [6–10]
Loss	11–11	Oct 2011	Linz Open, Austria	International	Hard (i)	Julia Görges	Marina Erakovic Elena Vesnina	5–7, 1–6
Loss	11–12	Feb 2012	Open GDF Suez, Paris, France	Premier	Hard (i)	Petra Martić	Liezel Huber Lisa Raymond	6–7(3–7), 1–6
Loss	11–13	Apr 2012	Stuttgart Open, Germany	Premier	Clay (i)	Julia Görges	Iveta Benešová Barbora Strýcová	4–6, 5–7
Loss	11–14	Jun 2012	Gastein Ladies, Bad Gastein, Austria	International	Clay	Petra Martić	Jill Craybas Julia Görges	7–6(7–4), 4–6, [9–11]
Loss	11–15	Sep 2012	Pan Pacific Open, Tokyo, Japan	Premier 5	Hard	Květa Peschke	Raquel Kops-Jones Abigail Spears	1–6, 4–6
Win	12–15	Oct 2012	Linz Open (2), Austria	International	Hard (i)	Květa Peschke	Julia Görges Barbora Strýcová	6–3, 6–4
Loss	12–16	Jan 2013	Brisbane International, Australia	Premier	Hard	Květa Peschke	Bethanie Mattek-Sands Sania Mirza	6–4, 4–6, [7–10]
Win	13–16	May 2013	Brussels Open, Belgium	Premier	Clay	Květa Peschke	Gabriela Dabrowski Shahar Pe'er	6–0, 6–3
Loss	13–17	Jun 2013	Nuremberg Cup, Germany	International	Clay	Květa Peschke	Raluca Olaru Valeria Solovyeva	6–2, 6–7(3–7), [9–11]
Loss	13–18	Aug 2013	Canadian Open, Toronto, Canada	Premier 5	Hard	Květa Peschke	Jelena Janković Katarina Srebotnik	7–5, 2–6, [6–10]
Loss	13–19	Aug 2013	Cincinnati Masters, United States	Premier 5	Hard	Květa Peschke	Hsieh Su-wei Peng Shuai	6–2, 3–6, [10–12]
Win	14–19	Feb 2014	Open GDF Suez, Paris, France	Premier	Hard (i)	Květa Peschke	Tímea Babos Kristina Mladenovic	6–7(7–9), 6–4, [10–5]
Loss	14–20	Oct 2016	Linz Open, Austria	International	Hard (i)	Květa Peschke	Kiki Bertens Johanna Larsson	6–4, 2–6, [7–10]
Win	15–20	May 2017	Prague Open, Czech Republic	International	Clay	Květa Peschke	Lucie Hradecká Kateřina Siniaková	6–4, 7–6(7–3)
Loss	15–21	Aug 2017	Canadian Open, Toronto, Canada	Premier 5	Hard	Květa Peschke	Ekaterina Makarova Elena Vesnina	0–6, 4–6
Win	16–21	Apr 2018	Stuttgart Open (2), Germany	Premier	Clay (i)	Raquel Atawo	Nicole Melichar Květa Peschke	6–4, 6–7(5–7), [10–5]
Loss	16–22	Oct 2018	Linz Open, Austria	International	Hard (i)	Raquel Atawo	Kirsten Flipkens Johanna Larsson	6–4, 4–6, [5–10]
Loss	16–23	Feb 2019	Qatar Ladies Open, Doha, Qatar	Premier	Hard	Demi Schuurs	Chan Hao-ching Latisha Chan	1–6, 6–3, [6–10]
Win	17–23	Apr 2019	Charleston Open, United States	Premier	Clay	Alicja Rosolska	Irina Khromacheva Veronika Kudermetova	7–6(9–7), 6–2
Loss	17–24	May 2019	Italian Open, Rome, Italy	Premier 5	Clay	Demi Schuurs	Victoria Azarenka Ashleigh Barty	6–4, 0–6, [3–10]
Loss	17–25	Jun 2019	Birmingham Classic, United Kingdom	Premier	Grass	Demi Schuurs	Hsieh Su-wei Barbora Strýcová	4–6, 7–6(7–4), [8–10]
Loss	17–26	Aug 2019	Canadian Open, Toronto, Canada	Premier 5	Hard	Demi Schuurs	Barbora Krejčíková Kateřina Siniaková	5–7, 0–6
Loss	17–27	Aug 2019	Cincinnati Open, United States	Premier 5	Hard	Demi Schuurs	Lucie Hradecká Andreja Klepač	4–6, 1–6

WTA 125 tournament finals

Doubles: 1 (1 title)

Result	W–L	Date	Tournament	Surface	Partner	Opponents	Score
Win	1–0	Mar 2016	San Antonio Open, United States	Hard	Nicole Melichar	Klaudia Jans-Ignacik Anastasia Rodionova	6–1, 6–3

Singles (12–2)

Outcome	No.	Date	Tournament	Surface	Opponent	Score
Winner	1.	4 August 2002	ITF Bad Saulgau, Germany	Clay	Ivana Zupa	6–3, 6–4
Winner	2.	26 January 2003	ITF Hull, United Kingdom	Hard (i)	Tessy van de Ven	7–6(4), 6–3
Winner	3.	15 June 2003	ITF Hamilton, Canada	Clay	Beier Ko	6–3, 6–3
Winner	4.	13 July 2003	ITF Vancouver, Canada	Hard	Vilmarie Castellvi	6–2, 6–4
Winner	5.	20 July 2003	ITF Oyster Bay, United States	Hard	Bethanie Mattek-Sands	6–3, 6–0
Runner-up	6.	2 May 2004	ITF Cagnes-sur-Mer, France	Clay	Séverine Beltrame	4–6, 4–6
Winner	7.	26 July 2004	ITF Modena, Italy	Clay	Selima Sfar	6–2, 6–4
Winner	8.	7 September 2004	ITF Denain, France	Clay	Dally Randriantefy	6–3, 6–2
Winner	9.	15 June 2008	ITF Zlín, Czech Republic	Clay	Jelena Kostanić Tošić	6–3, 4–6, 6–1
Winner	10.	22 June 2008	ITF Alkmaar, Netherlands	Clay	Marlot Meddens	6–1, 6–1
Winner	11.	29 June 2008	ITF Périgueux, France	Clay	Florence Haring	6–3, 6–3
Winner	12.	3 August 2008	ITF Rimini, Italy	Clay	Lourdes Domínguez Lino	6–1, 6–2
Runner-up	13.	17 August 2008	ITF Bronx, United States	Hard	Elena Bovina	3–6, 5–7
Winner	14.	23 April 2011	ITF Tessenderlo, Belgium	Clay (i)	Alison Van Uytvanck	6–3, 7–5

Doubles (6–1)

Outcome	No.	Date	Tournament	Surface	Partner	Opponents	Score
Winner	1.	13 September 2004	ITF Denain, France	Clay	Yuliana Fedak	Lubomira Bacheva Michaela Paštiková	1–6, 6–1, 6–2
Winner	2.	29 June 2008	ITF Périgueux, France	Clay	İpek Şenoğlu	Han Xinyun Xu Yifan	6–3, 6–4
Winner	3.	29 August 2009	ITF Bronx, United States	Hard	Vania King	Julie Coin Marie-Ève Pelletier	6–0, 6–3
Winner	4.	1 November 2010	ITF Ismaning, Germany	Carpet	Kristina Barrois	Tetyana Arefyeva Yuliana Fedak	6–1, 7–63
Winner	5.	22 April 2011	ITF Tessenderlo, Belgium	Clay	Tatjana Malek	Elina Svitolina Maryna Zanevska	7–5, 6–3
Winner	6.	8 May 2011	ITF Cagnes-sur-Mer, France	Clay	Petra Martić	Darija Jurak Renata Voráčová	1–6, 6–2, [11–9]
Runner-up	7.	24 July 2011	ITF Pétange, Luxembourg	Clay	Kristina Barrois	Johanna Larsson Jasmin Wöhr	6–72, 4–6