Updated

Brisbane, Australia (SportsNetwork.com) - World No. 1 superstar and reigning champion Serena Williams was an easy second-round winner Tuesday at the 2014 season-opening Brisbane International tennis event, a hardcourt Australian Open tune-up.

Williams had little trouble in a 6-4, 6-4 straight-set victory over former top-10 German and 2011 Brisbane runner-up Andrea Petkovic at Queensland Tennis Centre.

"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."

The reigning U.S. and French Open titlist Williams' quarterfinal opponent on Friday will be diminutive Slovak Dominika Cibulkova.

Meanwhile, fourth-seeded former No. 1 Jelena Jankovic, of Serbia, bested 19- year-old Ukrainian Elina Svitolina 6-1, 6-3.

Two other second-rounders saw Estonian Kaia Kanepi drub eighth-seeded Spaniard Carla Suarez Navarro 6-2, 6-2 and the No. 9 seed Cibulkova rally to take out 42-year-old Japanese Kimiko Date-Krumm 6-3, 1-6, 6-3. The 2012 Brisbane champion Kanepi will battle former world No. 1 Maria Sharapova in the quarters.

On Wednesday, second-seeded reigning Aussie Open champ Victoria Azarenka will take on Aussie qualifier Casey Dellacqua. Azarenka titled here in 2009 and was the Brisbane runner-up in 2008.

The third-seeded Sharapova was scheduled to meet Aussie qualifier Ashleigh Barty on Wednesday, but Barty pulled out of the match, citing a left adductor injury, thus giving Sharapova a walkover into the quarters.