Australian Open champion Angelique Kerber can celebrate deposing Serena Williams as world No.1 with a second grand slam title when she contests the US Open final.
Williams 186-week reign atop the rankings is over after she lost her semi-final to Karolina Pliskova 6-2 7-6 (7-5) at Flushing Meadows.
The 10th-seeded Czech moved into her first grand slam final, where she'll meet Germany's Kerber, who accounted for Caroline Wozniacki 6-4 6-3.
Lefthander Kerber, who leads the WTA for most main draw match wins this season at 53-14, clinched victory with a backhand that actually landed just beyond the baseline but went unchallenged by Wozniacki.
"It's just incredible. It's a great day," Kerber said.
"To be here in the final for the first time, that means a lot. To be No.1 in the world, it sounds amazing."
Kerber will become the second German to top the women's rankings, following Steffi Graf.
"For me, it's just amazing to be after Steffi the next number one player in Germany," said Kerber, who at 28 will become the oldest player to reach No.1.
The changing of the guard as women's top player also safeguarded Graf's share of the record for most consecutive weeks at the top.
The derailing of Williams' bid for a record-setting seventh US Open title kept the American stalled at 22 grand slam singles titles - tied with Graf for most in the Open era.
Kerber, who beat Williams in the Australian Open final for her first slam and fell to the same player in the Wimbledon title match, has one unfinished piece of business - getting even with Pliskova, who beat her in last month's Cincinnati final.
"I will try to take the revenge against her," said Kerber, who holds a 4-3 career edge over the big-serving Pliskova.
Pliskova's victory completed a Williams family double having also beaten Serena's older sister, sixth-seeded Venus, in the fourth round.
Williams clutched at her left hamstring occasionally in the second set and double-faulted to end it.
But a clearly annoyed Williams refused to use fatigue as an excuse for her loss and instead blamed her sluggishness more on left knee problems that limited her mobility.
"OK, I'm not going to repeat myself. I wasn't tired from yesterday's match," said Williams. "If I can't turn around after 24 hours and play again then I shouldn't be on tour.
"I have been having some serious left knee problems. I wasn't tired. Fatigue had absolutely nothing to do with it.
"I wasn't able to move the way I wanted to move."
