Serena strolls in Brisbane

Serena Williams eased past Andrea Petkovic 6-4 6-4 in her first competitive match of the season on New Year's Eve at the Brisbane International.

The world No 1 was understandably below her best after the off-season, making 36 unforced errors, but hit 35 winners and fired down 11 aces including one at 196 kph (122 mph) to bring up set point in the first.

"It was an intense match, which was really good," Williams said. "She's been in the top 10 before and she was on her way to being even better. It was a good match for me."

Williams began her stellar 2013 season by winning the title in Brisbane, the first of 11 that included two grand slams.

Williams had a win-loss record of 78-4 last season and spent all but seven weeks on top of the rankings, and she has not lowered her expectations for the year ahead.

"I had a similar question in 2012. I had such a good year winning two slams and a (Olympic) gold and two doubles. It was a lot," she said. "I just didn't think I could do better. Arguably I may have done better (in 2013), so I'm just going to be up for that challenge again."

In the quarter-finals she will face ninth-seeded Dominika Cibulkova, who overcame 43-year-old Japanese veteran Kimiko Date-Krumm 6-3 1-6 6-3.

Also in the second round, fourth-seeded Serb Jelena Jankovic beat Elina Svitolina of Ukraine 6-1 6-3.