Stanislas Wawrinka wins opener

KEY BISCAYNE, Fla. -- Stanislas Wawrinka bounced back from his first loss of the year with a victory Saturday at the Sony Open.

Playing at Key Biscayne for the first time since 2011, Wawrinka beat Daniel Gimeno-Traver 6-0, 3-6, 6-3.

Wawrinka, who won the Australian Open in January, improved to 14-1 this year. His lone defeat came last week in the fourth round at Indian Wells to Kevin Anderson.

Wawrinka has never reached the quarterfinals in five previous appearances at Key Biscayne, but then he has never been ranked this high.

"I'm No. 2 in the world," he said. "I know that if I play my best tennis I can be a favorite of the tournament. I know how well I can play."

Wawrinka hit 33 winners against Gimeno-Traver and shook off some sloppy play midway through the match.

"I was negative in the second set, a little bit stupidly, but then I'm really happy the way I start the third set," Wawrinka said. "First one here, it's never easy. The condition was really slow today, really humid. You need to get through."

Three-time champion Novak Djokovic was off Saturday but advanced to the fourth round anyway when his next scheduled opponent, Florian Mayer, withdrew because of a groin injury. Djokovic's next match will be Tuesday.

No. 1 Rafael Nadal began a bid for his first Key Biscayne title by beating Lleyton Hewitt 6-1, 6-3.

No. 10-seeded John Isner rallied to win an all-American matchup against Donald Young, 6-7 (5), 6-3, 6-4. Isner is back in the top 10 this week for the first time in 18 months.

Sam Querrey, Ryan Harrison and Jack Sock lost, leaving Isner as the only American remaining in the men's draw.

"The state [of U.S. tennis] is not the greatest it has ever been,'' Isner said.

No. 7 Tomas Berdych joined Wawrinka in the third round by beating Stephane Robert 7-6 (5), 6-1. Seeded men eliminated included No. 19 Jerzy Janowicz , No. 23 Gael Monfils, No. 25 Marin Cilic , No. 26 Gilles Simon and No. 27 Vasek Pospisil.

Information from The Associated Press was used in this report.