Stan Wawrinka cracked a joke about his age after upsetting top seed Andrey Rublev in Stockholm.

The three-time Grand Slam champion has struggled for form since turning 39 earlier this year and now sits at No. 217 in the world.

But he’s rediscovered some of his best tennis this week, winning back-to-back tour-level matches for the first time in 2024. He kept his run going on Friday, stunning Rublev to become the third-oldest man ever to reach an ATP semi-final.

Wawrinka has been rolling back the years in Stockholm. He made the most of his wildcard into the main draw by beating No. 6 seed Brandon Nakashima in his opening match.

The Swiss star then beat Alejandro Davidovich Fokina to become the oldest quarter-finalist in tournament history. And he continued his run, upsetting world No. 7 Rublev in two tiebreak sets.

It’s Wawrinka’s first top-10 win in 14 months and makes him the second-oldest man this century to beat a top-10 player. And the 39-year-old couldn’t help but poke fun of his age after winning 7-6(5) 7-6(5).

The on-court interviewer jokingly referred to Wawrinka as an “impressive young man” as he stepped up to the microphone. “For an old man it’s not too bad, huh?” the world No. 217 quipped.

“The key was to stay focused and positive with myself. Andrey is such an amazing player.

“Today I was feeling good on the court, I was moving well and I could start to dictate a little bit. And again, with so much support it’s always easier to fight on the court so thank you very much everybody.”

At 39 years and six months, Wawrinka is the third-oldest man to reach a semi-final since the ATP Tour was established in 1990. He sits behind Jimmy Connors and Ivo Karlovic.

After being told about the ‘oldest’ stats, Wawrinka replied: “I cannot change my age but as I said, most important for me is that when I enter the court I always fight, I always try to improve, I enjoy what I’m doing.

“The reason I keep doing it is to play matches like this with so many people, so much good energy on the court and I’m super happy to have a chance to play one more match tomorrow.”

It won’t get any easier for Wawrinka. The 16-time title winner will face world No. 13 Tommy Paul in the semi-final. But he will be hoping the fans can push him on to score another big win.

While he hails from Switzerland, Wawrinka has been taken in as something of a home favourite as his long-time coach Magnus Normal is Swedish

The 39-year-old will be hoping to follow in the footsteps of another tour veteran, Gael Monfils, who lifted the title in Stockholm last year. Aged 37 at the time, Monfils became the tournament’s oldest champion and ended his 20-month wait for a trophy.