Updated

Serena Williams, and Agnieszka Radwanska posted second-round victories at the 2012 U.S. Open on Thursday, but two-time champion Venus Williams was sent packing.

Venus, participating in the U.S. open for a 14th time, was bounced out of the tournament by sixth-seeded German Angelique Kerber, 6-2, 5-7, 7-5, in a match that lasted past midnight at Arthur Ashe Stadium.

This is the first season of Venus' career that she's has failed to reach at least the third round of a major. She committed 60 unforced errors Thursday.

Venus had trouble with the grip of her racket in the first set, which lasted 31 minutes. She had five double faults in the set and committed 15 unforced errors.

Kerber, a semifinalist last year, was on the verge of taking the match in the second set when she surged to a 5-4 lead after Venus, during her service game, delivered a return into the net.

Venus fired a 118 mph ace, her only one of the match during the 11th game of the second set. Williams then delivered a backhand winner to the corner for a 6-5 lead.

On the verge of winning the second set, Venus failed to take advantage of a poor drop shot from Kerber, who sent the ball into the open court to square the 12th game. Kerber saved another set point, but on the third one, returned a ball into the net.

Venus sent a crosscourt forehand winner for a 4-2 lead, but Kerber won the next two games.

Kerber converted a critical break point to go up 6-5 on Venus' long return. Kerber finished it out on Venus' return into the net.

"Today it was so tough, so close. Venus is such a great player," said Kerber, who moved to 19-3 in three-set matches this year. "I just tried to focus on me, try to play my game plan. I'm happy to be in the third round here."

Venus' younger sister, Serena, a former No. 1, a three-time champ and two-time U.S. Open runner-up, had no problems in a matchup with Maria Jose Martinez Sanchez of Spain 6-2, 6-4.

Serena, the fourth seed, was last year's U.S. Open runner-up to Australian Sam Stosur. She is the reigning Wimbledon and Olympic champion.

The second-seeded Radwanska dropped the first set before coming back to blitz Spaniard Carla Suarez Navarro 4-6, 6-3, 6-0 on the Grandstand court.

The quiet Radwanska, who has a chance to leave the U.S. Open as the top-ranked woman in the world, leads the WTA in Grand Slam match wins this year with 14. She finished runner-up to Serena Williams at Wimbledon this year.

Up next for Radwanska will be former world No. 1 Serb Jelena Jankovic, the 30th seed who handled Spaniard Lara Arruabarrena-Vecino 6-4, 6-2 on Day 4. Jankovic was the U.S. Open runner-up in 2008.

Sara Errani, the 10th seed from Italy, cruised past Russian Vera Dushevina, 6-0, 6-1.

Another former world No. 1 from Serbia, Ana Ivanovic, was an easy second-round winner Thursday. The 12th seed blew past Swedish veteran Sofia Arvidsson 6-2, 6-2 in 64 minutes at Ashe Stadium.

"I'm very happy about today's match, because she's a tough opponent," Ivanovic said.

The 24-year-old Ivanovic is a three-time Grand Slam finalist and captured Roland Garros in 2008.

Meanwhile, 13th-seeded diminutive Slovak Dominika Cibulkova snuck past capable Serb Bojana Jovanovski 7-6 (7-3), 7-6 (7-3), 14th-seeded Russian Maria Kirilenko cruised past Hungarian Greta Arn 6-3, 6-2, and 20th-seeded Italian Roberta Vinci saved a match point before edging Kazakhstan's Yaroslava Shvedova 3-6, 7-5, 7-5. The Olympic bronze medal runner-up Kirilenko was last week's New Haven runner-up to Czech star Petra Kvitova.

American Sloane Stephens beat German Tatjana Malek 5-7, 6-4, 6-2.

Other second-round winners were Bulgarian Tsvetana Pironkova, Russians Elena Vesnina, Olga Puchkova and Ekaterina Makarova, Belarus' Olga Govortsova, Spaniard Silvia Soler-Espinosa and Czech Andrea Hlavackova.