Tsitsipas, the No. 4 seed, was not at his best, but came through 7-6 7-5 against Croatian wildcard Borna Gojo.
Tsitsipas, who is currently sixth in the Pepperstone ATP Live Race To Turin standings, struck 26 winners and outpointed Gojo 84-76 en route to advancing against top-seeded Daniil Medvedev. In four previous Vienna appearances, Tsitsipas had never advanced beyond the second round.
“It feels great,” Tsitsipas said in his post-match interview inside Wiener Stadthalle. “I kept fighting and didn’t lose faith. In the tie-break, what a great way to end it by fighting and giving so much on the court. I felt it was a matter of keeping the ball deep and attacking when the ball was short."
Tsitsipas, who had never before been beyond the second round in Vienna, is chasing his second title of 2023 after the world No. 7 won Los Cabos in the summer.
For the first time since 1994, all of the top 4 seeds have reached the semifinals in Vienna.
Daniil Medvedev (1)
Jannik Sinner (2)
Andrey Rublev (3)
Stefanos Tsitsipas (4)
