Stan Wawrinka held off a spirited fightback from Denis Shapovalov to book his spot in the Rotterdam Open semifinals Friday.
Wawrinka, who won the Rotterdam title in 2015, let slip a 4-1 lead in the second set but recovered to secure a 6-4, 7-6 (4) quarterfinal victory over Canadian No. 10 seed Shapovalov in 1 hour, 30 minutes on court.
The Swiss will face top seed Kei Nishikori in Saturday's semifinal in Rotterdam, Netherlands, after the Japanese star beat Marton Fucsovics 6-3, 6-2.
No. 5 seed Daniil Medvedev toppled another in-form player in 2017 champion Jo-Wilfried Tsonga to set up a tantalizing final-four clash with Gael Monfils, who saw off Damir Dzumhur 6-1, 6-2.
Russia's Medvedev, who won the Sofia Open last week, proved too strong for the recently crowned Open Sud de France champion Tsonga in a 6-4, 6-2 win.
"It feels a little bit strange, as I didn't think I played that well," Medvedev said after his victory. "I managed to work hard. I don't think Jo was happy with his level, either, as we've both played a lot of matches. I think the match against Gael will be different, the conditions will be better for him here. I will need to fight."
Monfils will be looking to go one better in Rotterdam after making the final in 2016. The Frenchman will also be aiming for revenge after losing out to Medvedev in Sofia last Saturday.
He said: "I stuck to my game plan and I am satisfied how I executed. I prepared well in the offseason and I am starting to believe that I can get back to the top of the game."