Juniors

Rehnquist had an outstanding junior career, winning the Australian Open Boys' Singles in 1996 and reaching as high as No. 3 in the world in singles the same year (and No. 7 in doubles).

Singles: 2 (1 title, 1 runner-up)

Result	Year	Tournament	Surface	Opponent	Score
Win	1996	Australian Open	Hard	Mathias Hellström	2–6, 6–2, 7–5
Loss	1996	French Open	Clay	Alberto Martín	3–6, 6–7

Australian Open: W (1996)
French Open: F (1996)
Wimbledon: 3R (1995)
US Open: QF (1994)

Pro tour

The Swede competed in the 2006 Australian Open, losing to 20th seed Radek Štěpánek 6–1, 6–2, 6–2, and at the 2009 Australian Open, but lost in the first round 6–0, 6–2, 6–2 to eventual semi-finalist Andy Roddick.

Rehnquist won 5 Challenger titles in his career.

Singles: 15 (8–7)

Result	W–L	Date	Tournament	Tier	Surface	Opponent	Score
Loss	0–1	Jun 1999	Finland F1, Oulu	Futures	Clay	Johan Örtegren	4–6, 6–4, 3–6
Loss	0–2	Sep 1999	Norway F1, Oslo	Futures	Carpet	Johan Settergren	3–6, 2–6
Win	1–2	May 2000	USA F11, Tampa	Futures	Clay	Kristian Capalik	6–7(2–7), 7–5, 6–1
Win	2–2	Mar 2001	New Zealand F1, Ashburton	Futures	Hard	Chris Magyary	6–2, 5–7, 6–2
Loss	2–3	Mar 2001	New Zealand F2, Christchurch	Futures	Hard	Vasilis Mazarakis	0–6, 3–6
Win	3–3	Mar 2001	Hamilton, New Zealand	Challenger	Hard	Martin Lee	3–6, 6–2, 6–0
Loss	3–4	Apr 2001	Great Britain F3, Bournemouth	Futures	Clay	Todd Larkham	2–6, 0–6
Loss	3–5	Oct 2002	Burbank, United States	Challenger	Hard	Robby Ginepri	6–7(6–8), 1–6
Win	4–5	Apr 2003	Greece F2, Kalamata	Futures	Hard	Petr Kralert	6–0, 6–1
Win	5–5	Jun 2003	Atlantic City, United States	Challenger	Hard	Jeff Salzenstein	6–4, 6–4
Loss	5–6	Jun 2004	Tallahassee, United States	Challenger	Hard	Cecil Mamiit	4–6, 6–4, 5–7
Win	6–6	Nov 2005	Helsinki, Finland	Challenger	Hard	Tomáš Cakl	7–6(7–2), 7–6(7–4)
Loss	6–7	Sep 2006	Sweden F4, Gothenburg	Futures	Hard	Joachim Johansson	1–6, 6–7(4–7)
Win	7–7	Feb 2008	Guangzhou, China	Challenger	Hard	Danai Udomchoke	2–6, 7–6(7–4), 6–2
Win	8–7	Jul 2008	Manchester, United Kingdom	Challenger	Grass	Richard Bloomfield	7–6(10–8), 0–6, 6–3

Doubles: 7 (6–1)

Result	W–L	Date	Tournament	Tier	Surface	Partner	Opponents	Score
Win	1–0	Jun 1999	Finland F1, Oulu	Futures	Clay	Mikael Maatta	Mikhail Elgin Timo Nieminen	7–6, 6–4
Win	2–0	Oct 1999	Great Britain F11, Leeds	Futures	Hard	Nicklas Timfjord	Yves Allegro Olivier Patience	6–4, 7–6
Win	3–0	Oct 2000	Finland F1, Vierumäki	Futures	Hard	Matthis Kempe-Bergman	Mattias Pennonen Tobias Steinel-Hansson	3–6, 6–2, 7–5
Win	4–0	Mar 2001	New Zealand F2, Christchurch	Futures	Hard	Henrik Andersson	Luke Bourgeois Andrew Painter	3–6, 6–3, 6–2
Win	5–0	Sep 2001	Sweden F1, Gothenburg	Futures	Hard	Johan Kareld	Jonas Froberg Robin Söderling	7–6(7–3), 6–4
Win	6–0	Oct 2002	Burbank, United States	Challenger	Hard	Louis Vosloo	Daniel Melo Iván Miranda	7–6(8–6), 6–1
Loss	6–1	Apr 2006	Cardiff, United Kingdom	Challenger	Hard	Filip Prpic	Philipp Petzschner Alexander Peya	6–4, 3–6, [7–10]

Singles