NEW YORK, Aug. 31 (UPI) -- Serena Williams reached the third round of the U.S. Open Thursday while her sister Venus lost a late-night, marathon match against Angelique Kerber.
Second-seeded Agnieszka Radwanska, who has a chance to become the top-ranked player in the world during this tournament, had to rally against Carla Suarez Navarro to keep those hopes alive.
Serena Williams, who recently won singles and doubles titles at both Wimbledon and the Olympics, rolled to a 6-2, 6-4 victory over Maria Jose Martinez Sanchez. That will send her into the third round for a meeting with Ekaterina Makarova, who disposed of Elena Vesnina 6-3, 6-4.
Venus Williams, however, fell to Kerber 6-2, 5-7, 7-5 in a match that did not end until after midnight. Kerber is seeded sixth in this tournament.
Radwanska survived her second-round match against Suarez Navarro 4-6, 6-3, 6-0 and will now meet Jelena Jankovic, a former world No. 1 who downed Lara Arruabarrena Vecino 6-4, 6-2. Radwanska reached the finals at Wimbledon this year before losing to Serena Williams.
Other winners in the second round Thursday included Ana Ivanovic, Dominika Cibulkova, Maria Kirilenko and Roberta Vinci.
