Radwanska, Li advance; Serena rained out at U.S. Open

Third seed Agnieszka Radwanska and fifth-seeded Li Na were a pair of winners on a rainy Wednesday at the U.S. Open, while world No. 1 and defending champion Serena Williams had her second- rounder against Kazakhstan's Galina Voskoboeva postponed until Thursday.

The 16-time Grand Slam champion Serena is a four-time U.S. Open champ and two-time runner-up. She beat Victoria Azarenka in last year's final in Flushing and is also the reigning French Open champ.

Meanwhile, last year's Wimbledon runner-up Radwanska, of Poland, got past Spaniard Maria-Teresa Torro-Flor 6-0, 7-5 at Armstrong Stadium, while this year's Australian Open runner-up and the former French Open champion Li, of China, handled Swede Sofia Arvidsson 6-2, 6-2 at Ashe Stadium at the USTA Billie Jean King National Tennis Center. Radwanska will meet Russian Anastasia Pavlyuchenkova on Friday.

Li was happy to beat the rain on Day 3.

"It's tough for them," she said, referring to all the players who still had singles matches to complete. "For me, just relax all day and do whatever I want."

Also, 18th-seeded Spaniard Carla Suarez Navarro dropped American Coco Vandeweghe 6-3, 6-4 and a 32nd-seeded Pavlyuchenkova eased past Aussie Ashleigh Barty 6-4, 6-0.

In addition to Serena's match against Voskoboeva, officials also postponed matches involving No. 8 seed Angelique Kerber, No. 9 Jelena Jankovic and No. 25 Kaia Kanepi. Jankovic is a former No. 1 who lost to Serena in the 2008 U.S. Open finale.