NEW YORK (AP) -Defending U.S. Open champion Sam Stosur cruised into the fourth round of the U.S. Open, where she will face a teenager who has defeated former Grand Slam winners in her last two matches.
Eighteen-year-old Brit Laura Robson, who ended Kim Clijsters' career two days earlier, knocked out 2011 French Open champ Li Na 6-4, 6-7 (5), 6-2 on Friday.
The 89th-ranked Robson had never been past the second round of a major tournament or beaten a top-10 opponent before this year's U.S. Open. Now she's done both after eliminating the ninth-seeded Li.
Robson put her hands to her head in shocked joy after the Chinese star returned her serve long on the final point.
Stosur was pushed for the first time in this year's Open by American Varvara Lepchenko, but dominated the second set after winning the first in a tiebreaker.
The seventh-seeded Stosur won 7-6 (5), 6-2. She had dropped just five games through her first two matches.
It was still a successful Open for the 31st-seeded Lepchenko. After reaching at least the third round in three straight Grand Slam events, she'll likely climb into the top 30 in the rankings.
Friday night could be the farewell for 2003 champion Andy Roddick. A day earlier, he announced this would be the final tournament of his career.
The American is set to face Bernard Tomic in Arthur Ashe Stadium.
In earlier men's action, fourth-seeded David Ferrer won the first two sets in 62 minutes, then needed 65 minutes to clinch the third set in a tiebreaker that went 26 points. The Spaniard beat Igor Sijsling 6-2, 6-3, 7-6 (12) in the second round.