Top-seeded Caroline Wozniacki stretched her winning streak to 13 matches by beating 45th-ranked Dominika Cibulkova of Slovakia 6-2, 7-5 in the U.S. Open quarterfinals Wednesday.
Wozniacki, the 2009 runner-up at Flushing Meadows, will face No. 7 Vera Zvonareva in Friday's semifinals.
Playing her usual steady game, retrieving balls and forcing her opponent to hit shot after shot, Wozniacki handled the wind that was gusting at more than 34 mph (58 kph). She compared it to ''playing in a hurricane or something.''
American businessman Donald Trump watched from Wozniacki's player-guest box instead of his usual suite.
''He called my agent and asked if there was going to be a space in my box,'' Wozniacki said. ''I said, `Of course, there's always a place for Mr. Trump.'''
Wozniacki made only 18 unforced errors, while Cibulkova conceded 43 to play right into Wozniacki's way of winning. She gets more balls back than anyone on tour these days. Her first five opponents have averaged 33 unforced errors.
''It felt like we were playing in a hurricane or something,'' Wozniacki said. ''But it was the same for both players. I'm happy to get through.''
Midway through the second set, the generally unflappable Wozniacki got into an extended discussion with chair umpire Anthony Nimmons over a ruling that a point should be replayed. Cibulkova served and Wozniacki's return landed near the baseline; Cibulkova's subsequent forehand went out. But a line judge had called Wozniacki's return out, then corrected that call.
Nimmons decided that that changed call affected Cibulkova.
Wozniacki approached the chair and asked, ''How can you replay the point?''
Nimmons replied, ''In my eyes, she was hindered by him.''
To which Wozniacki responded, ''You've got to be kidding me,'' a phrase she would repeat as the argument continued.
Eventually, the point was replayed, and Cibulkova won it, and that game, part of a tight, tense set.
Her semifinal match is Friday against No. 7 Vera Zvonareva, a 6-3, 7-5 winner over No. 31 Kaia Kanepi.
