Angelique Kerber has reached the Cincinnati Open final, leaving her one win away from unseating Serena Williams as world No. 1.
Kerber took control after a 33-minute rain delay in the first set and beat Simona Halep 6-3 6-4 in humid, windy conditions, putting her within reach of the world's top ranking.
Williams has led the WTA rankings for 183 consecutive weeks, the second-longest such stretch.
A win on Sunday over 15th-seeded Karolina Pliskova would move Kerber to the top spot in next week's rankings. Williams dropped out at the start of the tournament because of an inflamed shoulder, leaving her ranking vulnerable.
Kerber has tried to avoid thinking about No. 1 because she didn't want to put any more pressure on herself. Now, there's no avoiding it.
"I've had a lot of ups and downs the last few years and a lot of experiences from which I've learned," Kerber said. "I think I'm one of the best tennis players.
"One match away, still a long way to go."
She'd become only the second German woman to hold the top spot. Steffi Graf's reign at No. 1 ended in 1997. It would be Kerber's first title in Cincinnati - she lost her other finals appearance in 2012.
Halep was on a hot streak, winning back-to-back titles at Bucharest and Montreal. She'd also beaten Kerber in their four matches on hard courts this season, although Kerber won at Wimbledon.
Kerber led 4-3 in the first set when rain forced the delay. She won eight of the next nine points to take the first set, then pulled ahead 4-0 in the second set, pumping her right arm in celebration as the games piled up.
Pliskova advanced to the championship match for the first time by beating Garbine Muguruza 6-1 6-3 in an earlier match. She was well aware of the stakes on Sunday.
"I know it," she said. "For me, doesn't really mean anything. For her, yes. I don't know if she would be a little bit stressed or something, but I would love to have her as a No. 1 after a few years. But I'll do anything for her not to get there, if she wins (in the semi-finals)."
