NEW YORK (AP) -- Sara Errani reached the quarterfinals at a Grand Slam event for the third time this year, beating Angelique Kerber in straight sets at the U.S. Open.

The 10th-seeded Italian won 7-6 (5), 6-3 on Monday. Before this year's Australian Open, she had never gotten past the third round at a major tournament.

Kerber made a surprise run to the U.S. Open semifinals a year ago and had advanced to at least the quarters at the French Open and Wimbledon in 2012.

Errani, the runner-up at Roland Garros, needed nearly 2 hours to win in two sets.

The sixth-seeded Kerber double-faulted to end the first-set tiebreaker. She had 38 unforced errors.

When Kerber's final forehand bounced off the net cord and back, Errani dropped her racket and pumped both fists.