Ash Barty lost her chance to regain the No.1 world ranking when the Australian was beaten in straight sets by Russian Svetlana Kuznetsova in the semi-finals of the Cincinnati Masters on Saturday.
Top seed Barty, who would have replaced the injured Naomi Osaka as the world's top-ranked player with a victory, struggled with the rhythm off her serve as she lost 6-2 6-4, losing eight consecutive games to the Russian at one point.
"I think it probably started with the serve for me," Barty said courtside after her defeat.
"I mean, giving Svetlana that many looks at second serves I know I'm not going to get free points off my first serve off Sveta.
Ashleigh Barty of Australia (R) shakes hands with Svetlana Kuznetsova of Russia after losing in straight sets during Day 8 of the Western and Southern Open. Source: Getty Images North America
"She's an incredible returner and retrieves a long way so is able to make a lot of returns.
"Just to be on the back foot of a lot of rallies from the start wasn't ideal. I felt like we have done well to fight all week and then to put ourselves in this position, but Sveta was unreal today."
Barty won the first two games, then lost the set as Kuznetsova, effectively handling the Australian's slices and serving well, won the next six.
Barty at one point called a medical time out to have her right ankle retaped.
But the streak continued in the second set with Kuznetsova winning the opening two games before Barty held.
The Australian rallied to within 4-3 and 5-4 before Kuznetsova served out the victory.
Kuznetsova, ranked world No.153, will play the winner of Saturday's later semi-final between Americans Madison Keys and Sofia Kenin for the title on Sunday.
Ashleigh Barty of Australia returns a shot to Svetlana Kuznetsova of Russia during Day 8 of the Western and Southern Open. Source: Getty Images North America
"It's amazing to play again on centre court," Kuznetsova said.
Winner of the US Open in 2004 and the French Open in 2009, the 34-year-old has struggled with injuries throughout her career but has now defeated eighth-seeded Sloane Stephens, Czech third seed Karolina Pliskova and now Barty in successive matches.
She entered the Cincinnati tournament as a wildcard after winning two matches in Toronto. Issues in obtaining a US visa kept her from defending her Washington DC title.
"Maybe one week or two weeks helped me back home," she said.
"Something important happened in my life and now I feel better."
