STOCKHOLM, Sweden (AFP) — Three-time Grand Slam champion Stan Wawrinka rolled back the years on Friday as the 39-year-old ousted top seed Andrey Rublev to reach the Stockholm semifinals.

Wawrinka, currently ranked 217th in the world, battled past seventh-ranked Russian Rublev, 7-6 (7/5), 7-6 (7/5) to notch his first win over a top-10 player this year.

The Swiss player next meets US fourth seed Tommy Paul, the 2021 Stockholm champion, who beat Serb Miomir Kecmanovic 7-6 (9/7), 6-2.

“I cannot change my age, but most important for me is that when I enter the court, I always try to fight,” said Wawrinka, the third-oldest semifinalist in modern ATP Tour history behind Jimmy Connors and Ivo Karlovic.

“I try to improve and enjoy what I am doing. The reason I keep going is to play matches like this, with so many people giving me good energy on the court, and I’m super happy to have the chance to play one more match tomorrow.”

The former world No. 3 fired down 14 aces, converting his first match point to reach the semi-final in the Swedish capital for the first time in four attempts.

“The key was to stay focused and positive with myself,” said Wawrinka, who had let a 2-0 lead in the second set slip. He is bidding for his 17th ATP title and first since Geneva in 2017.

Wawrinka won the Australian Open in 2014, the French Open in 2015 and the US Open in 2016.

Rublev’s hopes of qualifying for the eight-player ATP Finals for a fifth consecutive year took a knock as the 26-year-old Russian sits eighth with four players below him, including Paul, still competing this week.

World No. 37 Tallon Griekspoor knocked out second seed Casper Ruud 7-5, 7-6 (7/5) on the back of 13 aces and saved all three break points he faced.

Griekspoor now has three top 10 wins in his career and becomes the first Dutch semi-finalist in Stockholm since Sjeng Schalken won the title in 2001.

He will next face Bulgarian third seed Grigor Dimitrov who eased past Dominic Stricker of Switzerland 6-3, 6-2.