By Larry Fine
NEW YORK (Reuters) - Serena Williams gave a premature victory leap in her fourth-round match and later allowed herself a self-deprecating celebration after beating Kaia Kanepi to reach the U.S. Open quarter-finals on Monday.
World number one Williams is gunning for her third U.S. Open title in a row but for the moment, she saw her 6-3 6-3 victory over the Estonian as an important hurdle after failing to get past the fourth round in this year's other grand slams.
Williams jumped up and thrust her arms after 50th-ranked Kanepi netted a backhand on break point, but the mistake only made it 5-3 in the American's favor.
Top seeded Williams failed to serve out the match, but made amends by breaking Kanepi for the fourth time in the set to complete a 65-minute victory and advance to the last eight at Flushing Meadows.
"I finally made a quarter-final this year!" she shouted to the Arthur Ashe Stadium crowd with arms upraised. "Glad to do it in New York."
Williams will meet Italian 11th seed Flavia Pennetta, a semi-finalist last year who advanced with a 7-5 6-2 win against 29th-seeded Australian Casey Dellacqua.
Wimbledon champion Novak Djokovic became the first men's player into the quarter-finals, when the top-seeded Serb beat 22nd seed Philipp Kohlschreiber of Germany 6-1 7-5 6-4.
Djokovic will meet either eighth seed Andy Murray of Britain or ninth-seeded Frenchman Jo-Wilfried Tsonga.
Making the quarters would seem like old hat to Williams, who has won 17 career grand slam singles crowns and is bidding to become the first woman to win three U.S. titles in a row since Chris Evert claimed four straight from 1975-1978.
But this has been a frustrating season on the big stage for Williams, who lost in the fourth round in the Australian Open, the third round in Wimbledon and the second round at Roland Garros.
Williams admitted to anxious moments.
"I think I felt it in my serving game (in the second set) and I'm just pleased to make it to a grand slam quarters this year," she said.
"She hits the ball incredibly hard and she is able to move the ball around. I just keep fighting. And I just relaxed, I said, 'Serena, whatever happens, you're still in doubles'."
Serena and sister Venus Williams have already reached the quarter-finals of the women's doubles tournament.
Pennetta made the singles quarters for the fifth time in seven years with her straight-set victory.
The Italian was two points away from losing the opening set at 4-5, 15-30, before recovering, and then ran away with the second.
Pennetta, like her quarter-finals opponent Williams, is 32 years old, setting up a veteran clash in the last eight, in sharp contrast to Sunday's advance of 17-year-old Swiss Belinda Bencic, winner of last year's French and Wimbledon junior titles.
The Italian said too much was made of junior titles.
"For me, junior doesn't count," she said about expectations in the main draw of a grand slam. "For me we give too much important things to juniors. I mean, juniors are juniors. They are too young. They are baby.
"They still have to play, enjoy. It's completely different world, juniors to professional."
(Editing by Gene Cherry)