Defending champion Kim Clijsters briefly lost her step on a windy day before recovering in time to win her 15th straight match at the U.S. Open. The second-seeded Belgian beat Hungary's Greta Arn 6-0, 7-5 in the first round Monday. She fell behind 4-0 in the second set, and the 104th-ranked Arn had a chance to serve out the set at 5-4. But Clijsters got the break, then did it again to clinch the straight-set victory. Venus Williams landed awkwardly on her recently injured leg after hitting a swinging volley and grimaced. It was about the only glitch during her return to tennis. Playing for the first time in two months after spraining her left kneecap, Williams beat Roberta Vinci of Italy 6-4, 6-1 in the night match. http://sports.espn.go.com/sports/tennis/usopen10/news/story?id=5512227