He is the ATP title winner who is unbeaten against Jannik Sinner but is now retiring from professional tennis

Not many players can say they have never lost to Jannik Sinner after facing him.

Sinner is currently on the injury sidelines, having ended his season early due to a right knee injury.

Despite his recent woes, Sinner has still enjoyed a very successful 2026 season, having won his fifth Grand Slam title at Wimbledon and won every single match he has played at a Masters 1000 tournament.

Only three players have beaten Sinner this year, showing just how hard a feat it is to achieve. Mikhail Kukushkin also has a win against Sinner, and he has now retired from professional tennis.

Mikhail Kukushkin has retired from professional tennis

Kukushkin made his ATP Tour debut in 2007, and nearly 20 years later he is still competing.

The now 38-year-old, who represents Kazakhstan, had announced that he would be playing his final tournament at the Almaty Open, where Kukushkin had received a wildcard for.

Kukushkin won his first ATP Tour match in two years in his first round in Almaty, before both his run and career came to an end against Stefanos Tsitsipas, who beat him 7-6(5), 7-6(4).

This brings an end to a very respectable career for Kukushkin, who has been ranked as highly as world number 39. Kukushkin also won one ATP title in his career at the St. Petersburg Open and achieved his best Grand Slam result at Wimbledon in 2019, when he made it to the fourth round.

Kukushkin also obtained four top 10 wins in his career, including victories over both Stan Wawrinka and Grigor Dimitrov. Kukushkin also played Sinner earlier in his career at the St. Petersburg Open in 2019. This was when Sinner was just 18 years old, and experience showed as Kukushkin beat the Italian 6-3, 7-6(4).

Stefanos Tsitsipas sends message to Mikhail Kukushkin after he retires from tennis

While Kukushkin is not necessarily the biggest retirement of 2026, with the likes of Wawrinka and Gael Monfils also saying farewell to the sport, it is clear to see how respected he is by his peers.

Kukushkin has represented Kazakhstan since 2008, and is one of the Central Asian nation’s best ever players, and Tsitsipas has praised him for all he has done for the country after ending his career.

Tsitsipas wrote on X (formerly known as Twitter), “A big bravo to Mikhail Kukushkin, who was a trailblazer for Kazakh tennis in the 2010s. Wishing you the best in retirement, Mikhail!”

After ending his playing career, Kukushkin has confirmed his intention to now focus on his tennis academy that he opened in Spain.

In an interview with Clay, Kukushkin said, “Coaching at the academy I opened this summer in Spain. It’s a very small academy, not one of those huge mass academies; let’s say it’s a boutique academy where I pay attention to every player.

“It’s got off to a very good start and we have a lot of good players, so for the moment I’ll stay in tennis through that, but let’s see where I am in a few years.”