MASON, Ohio -- Top-ranked Jannik Sinner outlasted Alexander Zverev in a third-set tiebreaker Sunday to reach the final of the Cincinnati Open, while No. 1 Iga Swiatek was defeated in the women's semifinals by No. 3 Aryna Sabalenka.
Sabalenka will face American Jessica Pegula in Monday's final, while Sinner will play either American Frances Tiafoe or No. 15 seed Holger Rune.
Sinner emerged with a 7-6 (9), 5-7, 7-6 (4) victory after 3 hours, 7 minutes, tying Casper Ruud for the ATP Tour lead by reaching his fifth final of the season. Sinner leads the tour with four titles this season.
The first set lasted more than an hour and the match also was suspended for 30 minutes by rain.
Zverev, the No. 4 seed, had won four straight meetings against Sinner. Sinner finished with a 124-121 edge in total points.
"I think we both raised our level when it counted," Sinner said. "The tiebreaker can go both ways. I just tried to stay there mentally. Obviously, I'm happy to be in the final."
Sinner, who's been dealing with a right hip issue, was seen grabbing that area early in Sunday's match but said he came through fine physically.
"Sometimes I feel it," Sinner said. "I have to check after this tournament here. I haven't had too much time to recover before coming here. I'm not worried yet. I'm happy to play."
Sabalenka reached the finals in Cincinnati for the first time with a 6-3, 6-3 victory over Swiatek, ending the five-time Grand Slam winner's 15-match winning streak and avenging losses in the finals in Madrid and Rome.
"Really happy with the win, especially against Iga, who is always a tough battle," Sabalenka said. "To get the win in straight sets, that's kind of an achievement for me."
Swiatek, who's been on top of the WTA rankings for 116 weeks, was satisfied with her week in Cincinnati.
"I pretty much did better than I expected, honestly, especially on this surface," Swiatek said. "I'm happy with the result anyway, and already focusing on what I need to do to feel even better in New York."
The US Open begins there on August 26. Swiatek won the title in 2022.
Pegula, the No. 6 seed, beat Paula Badosa 6-2, 3-6, 6-3 after their semifinal was suspended more than an hour by rain.
She is the third American to reach the finals at the Canadian and Cincinnati Open in a calendar year, the first since Serena Williams in 2013.
"We've had a lot of great battles in the past," Sabalenka said. "She's a great player. Going to be another great match."