Toronto - Unseeded Romanian Sorana Cirstea sent defending champion Petra Kvitova packing on Friday in the quarter-finals of the WTA Toronto tournament.
Cirstea rallied for a 4-6, 7-5, 6-2 victory over sixth-seeded Kvitova and advanced to a semi-final clash with China's Li Na, the woman Kvitova beat in the final last year when the tournament was held in Montreal.
Li battled through a tight first set then coasted to a 7-6 (7/1), 6-2 victory over Dominika Cibulkova to reach the final four.
The fourth seed from China, playing her first tournament since a quarter-final appearance at Wimbledon, needed an hour and 36 minutes to get past unseeded Slovakian Cibulkova, who launched her hardcourt build-up to the US Open with the Stanford title a fortnight ago.
Li admitted she was a bit weary after a tough, three-set win over former world number one Ana Ivanovic on Thursday. She didn't feel like she was hitting a lot of winners, and was pleased to see in the match statistics that she fired 33 winners.
Getting through the first-set tiebreaker gave her a boost.
"After the first I was thinking "OK, one set in the pocket" so I was feeling more confident, of course," she said.
Third-seeded Agnieszka Radwanska also reached the semi-finals, with a 7-6 (7/1), 7-5 victory over fifth-seeded Sara Errani.
In a match that featured a total of 15 service breaks, Poland's Radwanska managed to hold in the final game of the contest to secure the victory and avenge a quarter-final loss to the Italian at Roland Garros this year.
After an early exchange of breaks in the third set, Radwanska broke Errani for a 5-4 lead, but dropped her serve in the next game.
She broke Errani again for a 6-5 lead and a chance to serve for the match, and this time made no mistake, taking a 40-15 lead and securing the win after two hours and one minute with a thumping forehand that Errani couldn't get back.
In the semi-finals world number four Radwanska will face either world number one Serena Williams or Slovakian Magdalena Rybarikova.
While Rybarikova is unseeded in this $2.369 million tournament she arrived in Toronto riding the momentum of a second straight title in Washington.