Updated

World No. 1 and four-time U.S. Open titlist Serena Williams breezed past Yaroslava Shvedova 6-3, 6-1 on Friday to move into the fourth round at the U.S. Open.

The reigning U.S. and French Open champ Williams, a 16-time Grand Slam winner, needed just over an hour to dispose of Shvedova in straight sets on the hardcourts at the USTA Billie Jean King National Tennis Center.

Williams, who defeated Victoria Azarenka in last year's outstanding final in Flushing, will take on fellow American Sloane Stephens in the round of 16 after the 15th-seeded Stephens downed No. 23 Jamie Hampton 6-1, 6-3.

The Aussie Open semifinalist Stephens is now an impressive 15-3 at the Slams this year.

A pair of top-five seeds -- Agnieszka Radwanska and Li Na -- also moved into the fourth round at the U.S. Open on Friday.

The third-seeded 2012 Wimbledon runner-up Radwanska topped 32nd-seeded Russian Anastasia Pavlyuchenkova 6-4, 7-6 (7-1), while the fifth-seeded former French Open champion and two-time Australian Open runner-up Li popped 11 aces in taking care of 30th-seeded 19-year-old British left-hander Laura Robson 6-2, 7-5.

Li avenged a third-round loss against Robson at last year's U.S. Open.

"I was really happy how I was hitting on the court," Li said. "And I thought I served really well."

Robson, who piled up 30 unforced errors on a sunny Day 5, was the first British woman to be seeded at a Grand Slam event since Jo Durie at the 1987 Australian Open.

Last month's Wimbledon semifinalist Radwanska is seeking her first-ever trip into a U.S. Open quarterfinal, while the 31-year-old Li reached her lone quarterfinal in New York City four years ago.

Nine-time Grand Slam winner Martina Hingis, who was named to the International Tennis Hall of Fame in July, made her first Grand Slam appearance since returning from retirement by pairing with Czech Daniel Hantuchova for a doubles match against Italy's Sara Errani and Roberta Vinci.

However, Hingis and Hantuchova were no match for the Italians, who earned a 6-3, 7-5 victory to advance.

Hingis later returned for a mixed doubles match with India's Mahesh Bhupathi against Sweden's Robert Lindstedt and Taiwan's Chan Yung-January, but Hingis and Bhupathi were handed a 7-6 (7-5), 7-6 (7-5) setback.

Eight-seeded Angelique Kerber of Germany cruised past 25th-seeded Kaia Kanepi of Estonia 6-0, 6-4, while 18th-seeded Carla Suarez Navarro notched a 6-2, 6-4 triumph over China's Zheng Jie.

Ninth-seeded former world No. 1 Jelena Jankovic reached the round of 16 with a 6-4, 7-6 (7-5) victory over Japan's Kurumi Nara. Jankovic was the 2008 U.S. Open runner-up and will battle Li in a quality fourth-round matchup here on Sunday.

Meanwhile, 24th-seeded Russian Ekaterina Makarova sent 16th-seeded Wimbledon runner-up Sabine Lisicki packing in 6-4, 7-5 fashion. The German slugger Lisicki has never advanced beyond the fourth round in Flushing.

Makarova will face Radwanska on Sunday in her first-ever fourth-round match at the U.S. Open.