Brisbane, Australia - Serena Williams joked that since the calendar still read 2012, she needed to maintain this year's dominant form.

The 15-time Grand Slam champion opened her 2013 season Sunday, and Williams needed less than an hour to beat fellow American Varvara Lepchenko 6-2, 6-1 in the first round of the Brisbane International.

Williams won 31 of her last 32 matches during the 2012 season, including titles at Wimbledon, the Olympics, the U.S. Open and the WTA Championships. She was 58-4 overall.

"Tomorrow is the last day of the year, so technically I still had my 2012 rep on the line," she said. "I really needed to win today so I could finish the year with still just the four losses. So that was important for me."

The third-ranked Williams didn't show any signs of the minor surgery on her big toes that forced her to withdraw from an exhibition in Thailand. She moved freely throughout the match against the 21st-ranked Lepchenko.

Williams saved five break points in the first game as she adjusted to a strong breeze.

"I was a little nervous, but I was completely fine," Williams said. "The doctor said I would be fine."