US Open 2011: Wozniacki, Williams Advance to Quarterfinals

World no.1 Caroline Wozniacki and 13-time Grand Slam winner Serena Williams moved on to the quarterfinals of the US Open 2011 with hard-fought victories in the 4th round on Monday.

Wozniacki, who suffered a fourth-round exit at Wimbledon in June, turned back 2004 US Open champion Svetlana Kuznetsova despite losing the first set. Kuznetsova took the first-set tiebreaker 8-6 before Wozniacki leveled the match by taking the second set, 7-5. The top seeded Dane then dominated the final set, 6-1, to get a spot in the Final 8.

Earlier, Williams responded to everything Ana Ivanovic could offer as the 29-year-old American defeated her 23-year-old Serbian opponent in straight sets, 6-3, 6-4, to move three wins away from her 14th Major singles championship. Williams served up nine aces as her vaunted serve again took center stage in 4th-round match that featured two former top-ranked players.

Waiting for Wozniacki in the quarterfinals is 10th seed Andrea Petkovic while Williams will have to take care of Anastasia Pavlyuchenkova to book a semifinal ticket.