GENEVA (AP) — Top-seeded Alexander Zverev advanced to the Geneva Open semifinals by beating Hugo Dellien 7-5, 3-6, 6-3 on Thursday.

The fifth-ranked Zverev saved a set point when trailing 5-3 against the 92nd-ranked Bolivian in the first. He then got the key service break to take a 3-1 lead in the decider.

"I struggled a little bit but still ended up finding a way to win, and that's most important for me right now," said Zverev, who has yet to win a title in 2019.

Zverev next faces Federico Delbonis or Albert Ramos-Vinolas, who could not complete their quarterfinal in fading light. Delbonis led 7-6 (5), 2-3.

Fifth-seeded Radu Albot beat Bosnian qualifier Damir Dzumhur 6-3, 7-5. The 45th-ranked Moldovan next faces Nicolas Jarry of Chile, who won 6-1, 7-5 against Japan's Taro Daniel.