Caroline Wozniacki ousted in London

— -- LONDON -- Former No. 1 Caroline Wozniacki is out of Wimbledon after losing 6-2, 7-5 to unseeded Barbora Zahlavova Strycova of the Czech Republic in the fourth round on Monday.

The 43-ranked Zahlavova Strycova has beaten seeded players in three consecutive matches.

Zahlavova Strycova, who had never beaten Wozniacki in three meetings, needed six match points to advance.

She will meet either 2011 champion Petra Kvitova or Peng Shuai in the quarterfinals.

Wozniacki saved two match points in the 10th game and three more in the 12th before the Czech player prevailed. Wozniacki, who was serving, hit the ball wide after a Zahlavova Strycova drop shot.

Also leaving Wimbledon was American  Madison Keys, who withdrew from her uncompleted third-round match because of a left thigh injury, allowing Yaroslava Shvedova of Kazakhstan to advance.

The two were scheduled to resume their third-round match in a second-set tiebreaker on Monday.

"I came in this morning and I had lots of tape on and I tried," the 30th-ranked Keys said. "I had so much tape on me I could barely walk. It just wasn't happening."

After Shvedova won the first set 7-6 (7), the two were level at 6-6 in the second set when darkness suspended their match on Saturday.

Keys has been advised to rest for two weeks before she can resume training.

Keys, the youngest player in top 50 at 19, won her first tour title at the Eastbourne grass-court Wimbledon warm-up.

"Really happy that I was able to title last week," she said. "I've just got to learn from the things that happened, the good and the bad, just try to use it for the hard courts. Just have to go and get ready for the US Open Series."

Shvedova will next face the winner of the match between Ana Ivanovic and Sabine Lisicki.

The Associated Press contributed to this report.