Williams beats Wozniacki at U.S. Open

Serena Williams returns a shot to Caroline Wozniacki of Denmark during a semifinal match at the U.S. Open tennis tournament in New York, Saturday, Sept. 10, 2011.
Matt Slocum

NEW YORK - Serena Williams hit 11 aces Saturday night at the U.S. Open in a 6-2, 6-4 victory over top-seeded Caroline Wozniacki that left Williams one win away from her 14th Grand Slam title.

This was Williams' first appearance in the U.S. Open semifinals since 2009, when a foot-fault call led to a tirade against the referee that cost her match point against Kim Clijsters.

Williams never came close to being pushed in this one and finished with 34 winners.

Williams will try for her fourth U.S. Open title Sunday against No. 9 Samantha Stosur, who beat Angelique Kerber 6-3, 2-6, 6-2.

The 2010 French Open runner-up, Stosur had two record-setting three-set wins earlier in the tournament, so this 1-hour, 46-minute match seemed like a breeze in comparison. She went up 5-0 in the final set, then was broken when she first tried to serve out the match.

The second time, Stosur had to save four break points before finally clinching victory with an emphatic backhand volley.

Stosur lost a tight 6-4, 7-6 (2) final to Francesca Schiavone at Roland Garros last year, wasting a break point in the second set.

"It had never happened up until that point, so you never know if it is going to happen again," she said. "Multiple people came up to me and said, 'You're gonna get another chance. You can come back and make it again.' Of course you want to believe that, but until it happens, you never know if that's the case."

Kerber had never been past the third round of a Grand Slam before this tournament. The German still hasn't beaten a top-10 opponent — she hadn't faced any player ranked better than No. 13 in her run at the Open.

Stosur needed 3 hours, 16 minutes to win in the third round against Nadia Petrova 7-6 (5), 6-7 (5), 7-5 — the longest women's match at the Open since the advent of the tiebreaker in 1970. Two days later, Stosur was part of the longest tiebreaker in a women's Grand Slam, beating Maria Kirilenko 6-2, 6-7 (15), 6-3.

This semifinal wasn't on the center court of Arthur Ashe Stadium because rain delays meant there were four singles matches Saturday instead of the normal three. It had to be played in Flushing Meadows' third-largest venue because of water on the court at Louis Armstrong Stadium.

Stosur and Kerber pleaded with tournament officials that their match belonged on Ashe, to no avail.

"I think it was not fair for us that the semifinal of the Grand Slam is on the Grandstand," Kerber said.

She still felt a bit overwhelmed in the setting — under the lights and in front of a packed house as fans with tickets to the night session waited for the men's matches to end so they could get into Ashe.