Serena Williams advances to U.S. Open’s fourth round

NEW YORK — 

— Serena Williams called herself “motivated” during her 6-4, 6-0 third-round win Saturday at the U.S. Open over Russia’s Ekaterina Makarova.

Sometimes “motivated” is just another word for “revenge.”

Williams was upset by Makarova at this season’s first major tournament, the Australian Open.

On Saturday, Williams was willing to be patient and construct points shot by shot from the baseline, and she was able to pounce suddenly, with an ace or an unexpected volley.

“I was motivated,” Williams said. “Knowing that I lost to her in Australia, it could definitely happen again. And I did not want that to happen again.”

When Makarova upset Williams at the Australian Open, it was because she made the American run and run at a time when Williams was still getting back into shape. Williams had spent the end of the 2010 season and the beginning of 2011 recovering from a pair of foot surgeries and subsequent complications.

And on Saturday, Makarova played Williams evenly for the first eight games. The match was tied at 4-4 when Williams raised her level.

“I was trying to get a service break,” Williams said, “and I started playing a little better, a little more consistent.”

Also advancing to the women’s fourth round was second-seeded, 23-year-old Agnieszka Radwanska of Poland, who beat 30th-seeded Jelena Jankovic, 6-3, 7-5.

Radwanska lost to Williams in a three-set championship final at Wimbledon in July. Radwanska has never been past the fourth round here.

Sloane Stephens, a peppy 19-year-old who was raised in Southern California and Florida, seemed on the verge of a major upset, but Stephens couldn’t take advantage of early momentum and fell to 12th-seeded Ana Ivanovic 6-7 (4), 6-4, 6-2 in a night match.

And Kim Clijsters, a three-time U.S. Open singles champion, officially played her last match as a pro. She and Bob Bryan were defeated in mixed doubles, 6-2, 3-6, 12-10 by Makarova and Bruno Soares.

Clijsters said she knows her decision to retire is the correct one. “It feels right,” she said. “I haven’t been crying. I think that’s just a sign it’s the right choice.”

Top-seeded Roger Federer smoothly moved into the fourth round of men’s singles. Federer had no trouble with talented Spaniard and 25th-seeded Fernando Verdasco. Federer won, 6-3, 6-4, 6-4.

Among the many things Federer did well Saturday was hit his volleys. He won 26 of 27 points attempted at the net.

“I had no clue my stats were that good,” Federer said. “When I do come in, it’s probably on shots I can be very offensive on.”

New Olympic gold medalist Andy Murray had much more of a struggle. Murray — who is seeded third and has never won a Grand Slam singles title — outlasted another Spaniard, winning 7-6 (5), 7-6 (5), 4-6, 7-6 (4) over 30th-seeded Feliciano Lopez.

Jack Sock, a 19-year-old from Nebraska who had received a wild card into the main draw, finally ran out of energy. In a match in which he had to call the trainer to work on his legs and arms, Sock lost to 11th-seeded Spaniard Nicolas Almagro, 7-6 (3), 6-7 (4), 7-6 (2), 6-1. For the 27-year-old Almagro, this marks the first time he has advanced as far as the fourth round at the U.S. Open.

Sock was trying to become the first teenage male to reach the fourth round here since Juan Martin del Potro and Kei Nishikori did it in 2008. Sock said his forearm gets tight, and that was why he had it massaged during the match.

“I played three events and practiced a lot before I got here,” Sock said. “There is a lot of wear and tear on it.”

diane.pucin@latimes.com

twitter.com/mepucin