Second seed Agnieszka Radwanska survived a potentially tricky test against Jelena Jankovic to reach the fourth round at the US Open.
The Pole has never gone beyond the last 16 at Flushing Meadows and had to come from a set and a break down in her last match against Carla Suarez Navarro, while she is also carrying a right shoulder problem.
But she was the more solid player throughout, moving well and frustrating Jankovic, and - although the second set was close - Radwanska came through impressively to win 6-3 7-5.
In the fourth round she will play in-form Italian Roberta Vinci, the 20th seed, who ousted 13th seed Dominika Cibulkova 6-2 7-5.
Vinci, who won the WTA Tour title in Dallas last weekend, has her work cut out if she is to make the quarter-finals, though, having lost to Radwanska in all their previous four meetings.