2014–15: First ITF title

In December 2014, Leshem lost in the final of the Israeli national championships in Ra'anana to Dudi Sela, 6–1, 6–2.^[3]

In November 2015, Leshem won the Israel F15 in Tel Aviv, Israel.^[4]

2016–17: ATP and top 250 debut

In June 2016 Leshem won both the Israel F9 in Kiryat Shmona, Israel, and the Israel F10 in Akko, Israel.^[4]

In April 2017, Leshem won both the Israel F3 in Tel Aviv, Israel, defeating Matias Franco Descotte in the final, and the Israel F4 in Ramat Gan, Israel, defeating Mats Moraing in the final.^[4] In May 2017 he won the Israel F6 in Akko, Israel, defeating Ben Patael in the final.^[4]

He made his debut at the 2017 Citi Open in Washington as a qualifier where he lost to Marcos Baghdatis in the first round.^[5]

2018–19

He was elected to receive a $25,000 grant through the Grand Slam Development Fund for 2018.^[6]

In June 2018, Leshem won the doubles with Daniel Cukierman in the Israel F8 in Tel Aviv, Israel, defeating Dan Added and Albano Olivetti in the finals, and the singles in the Israel F9 in Netanya, Israel, defeating Alessandro Bega in the final.^[4]

In September 2019 he won his ninth ITF title, the M25 in Ust-Kamenogorsk, Kazakhstan, defeating Konstantin Kravchuk in the final.^[4]

2022: First ATP win, Israeli No. 1 player

At the 2022 Tel Aviv Open, his home tournament, he qualified for the main draw having received a wildcard. He defeated seventh seed Lorenzo Giustino and third seed Luca Nardi. He recorded his first ATP career win defeating compatriot, wildcard Yshai Oliel.^[7][8] As a result, he climbed close to 70 positions up the rankings to No. 377 and became the No. 1 Israeli player in singles on 3 October 2022.

Davis Cup

He was called up to play for the Israel Davis Cup team at the age of 17 in February 2015, after the retirement of Andy Ram.^[3] Leshem played for the team against the Romania Davis Cup team in 2015, losing in singles to world # 159 Adrian Ungur by a score of 6–4, 6–2.^[9] In doubles, he and Bar Botzer lost to Florin Mergea (world doubles # 17) and Horia Tecău (world doubles # 9), 6–3, 6–4, 6–4.^[10][11] In 2020 in the G1 Israel vs Turkey Round 1 he defeated Cem Ilkel, ranked # 195 in the world.^[4]

Singles: 20 (9–11)

Result	W–L	Date	Tournament	Tier	Surface	Opponent	Score
Win	1–0	May 2015	Israel F6, Akko	Futures	Hard	Peter Kobelt	6–4, 6–2
Win	2–0	Nov 2015	Israel F15, Tel Aviv	Futures	Hard	Lennert Van der Linden	6–1, 5–7, 6–3
Loss	2–1	May 2016	Israel F7, Tel Aviv	Futures	Hard	Nicolas Meister	6–7(3–7), 5–7
Win	3–1	Jun 2016	Israel F9, Kiryat Shmona	Futures	Hard	Nick Chappell	6–3, 6–3
Win	4–1	Jun 2016	Israel F10, Akko	Futures	Hard	Nick Chappell	6–2, 6–1
Loss	4–2	Mar 2017	Israel F1, Ramat HaSharon	Futures	Hard	Enzo Couacaud	4–6, 4–6
Loss	4–3	Mar 2017	Israel F2, Ramat HaSharon	Futures	Hard	Enzo Couacaud	5–7, 1–6
Win	5–3	Apr 2017	Israel F3, Tel Aviv	Futures	Hard	Matias Franco Descotte	6–4, 6–1
Win	6–3	Apr 2017	Israel F4, Ramat Gan	Futures	Hard	Mats Moraing	6–3, 5–5 ret.
Win	7–3	May 2017	Israel F6, Akko	Futures	Hard	Ben Patael	6–3, 6–3
Loss	7–4	May 2017	Israel F7, Herzlia	Futures	Hard	Filip Peliwo	6–4, 1–6, 6–7(5–7)
Loss	7–5	Dec 2017	Israel F16, Ramat HaSharon	Futures	Hard	Yannick Mertens	6–7(4–7), 3–6
Win	8–5	Jun 2018	Israel F9, Netanya	Futures	Hard	Alessandro Bega	6–2, 6–1
Loss	8–6	Oct 2018	Israel F14, Meitar	Futures	Hard	Baptiste Crepatte	6–7(8–10), 3–6
Loss	8–7	Mar 2019	M15 Tel Aviv, Israel	World Tennis Tour	Hard	Quentin Robert	3–6, 6–2, 1–6
Win	9–7	Sep 2019	M25 Ust-Kamenogorsk, Kazakhstan	World Tennis Tour	Hard	Konstantin Kravchuk	2–2 ret.
Loss	9–8	May 2021	M15 Jerusalem, Israel	World Tennis Tour	Hard	Zane Khan	3–6, 4–6
Loss	9–9	May 2022	M25 Nottingham, United Kingdom	World Tennis Tour	Hard	Billy Harris	4–6, 3–6
Loss	9–10	Jun 2022	M15 Ra'anana, Israel	World Tennis Tour	Hard	Robert Strombachs	6–7(4–7), 4–6
Loss	9–11	Aug 2022	M25 Tbilisi, Georgia	World Tennis Tour	Hard	Bu Yunchaokete	3–6, 6–2, 3–6

Doubles: 13 (4–9)

Result	W–L	Date	Tournament	Tier	Surface	Partner	Opponents	Score
Loss	0–1	Oct 2013	Israel F15, Herzlia	Futures	Hard	Mor Bulis	Scott Clayton Toby Martin	4–6, 0–6
Win	1–1	May 2015	Israel F5, Ashkelon	Futures	Hard	Daniel Cukierman	Sam Barry Evgeny Karlovskiy	7–5, 7–5
Loss	1–2	Sep 2015	Israel F11, Kiryat Gat	Futures	Hard	Mor Bulis	Jarryd Chaplin Ben McLachlan	6–7(2–7), 2–6
Loss	1–3	May 2016	Israel F7, Tel Aviv	Futures	Hard	Daniel Cukierman	Nicolas Meister Hunter Reese	5–7, 5–7
Loss	1–4	Oct 2017	Ortisei, Italy	Challenger	Hard	Jeremy Jahn	Sander Arends Antonio Šančić	2–6, 7–5, [11–13]
Win	2–4	Jun 2018	Israel F8, Tel Aviv	Futures	Hard	Daniel Cukierman	Dan Added Albano Olivetti	6–4, 6–2
Loss	2–5	Feb 2019	M25 Oberentfelden, Switzerland	World Tennis Tour	Carpet	Albano Olivetti	Marek Jaloviec Michael Vrbenský	5–7, 1–6
Loss	2–6	Sep 2019	M25 Bagnères-de-Bigorre, France	World Tennis Tour	Hard	Albano Olivetti	Jonathan Eysseric Tom Jomby	1–6, 6–3, [3–10]
Loss	2–7	Feb 2022	M15 Oberhaching, Germany	World Tennis Tour	Hard	Colin Sinclair	Petr Nouza Giovanni Oradini	6–3, 3–6, [11–13]
Loss	2–8	May 2022	M25 Nottingham, United Kingdom	World Tennis Tour	Hard	Omar Jasika	Julian Cash Henry Patten	3–6, 7–5, [2–10]
Win	3–8	May 2022	M15 Akko, Israel	World Tennis Tour	Hard	Daniel Cukierman	Giles Hussey Daniel Little	6–3, 6–4
Win	4–8	Jan 2023	M25 Sunderland, Great Britain	World Tennis Tour	Hard	Daniel Cukierman	Anton Matusevich Joshua Paris	2–6, 6–1, [10–3]
Loss	4–9	Jun 2023	M25 Rome, Italy	World Tennis Tour	Clay	Julian Ocleppo	August Holmgren David Pichler	4–6, 5–7