Serena takes a tumble, but wins 6-0 6-0
While defending champion Victoria Azarenka won her way into the Australian Open second round, Serena Williams is under an injury cloud.
Williams, the third seed, turned on her right ankle while chasing down a return in the opening set of her first-round match. She was forced to take a medical time out to have the ankle rebandaged. She also had her left ankle strapped.
When she resumed she moved tentatively but relied on her powerful serve and booming returns to end the match against Romanian Edina Gallovits-Hall as quickly as possible. In the end she walked off court quickly after a 6-0 6-0 victory.
Despite the scoreline, Williams' ability to withstand a two-week grand slam tournament is in doubt. She was later joined by Azarenka, who beat Romanian Monica Niculescu 6-1 6-4.
"I started well but I struggled a little in the second set," Azarenka said.
"But I'm glad I'm still winning."
Earlier Danish star Caroline Wozniacki overcame a wildly erratic Sabine Lisicki to squeeze into the second round of the Australian Open.
The former world No.1 and 10th seed, was baffled by Lisicki's high-risk game before finally winning 2-6 6-3 6-3.
Wozniacki was lost in the opening set and trailed 3-1 in the second before clawing her way back into the match.
Lisicki managed to hit 33 more winners than the Dane - but was hurt by her unforced errors - 57 compared to eight.
Lisicki had a 2-1 winning record going into the match but Wozniacki should have an easier second round encounter when she meets the winner of the match between Czech Andrea Hlavackova and Croatian Donna Vekic.
Meanwhile, Japanese veteran Kimiko Date-Krumm rolled back the years to pull of a major upset. The 42-year-old crushed 12th-seeded Russian Nadia Petrova 6-2 6-0 in just over an hour.
Italian seventh seed Sara Errani's Open campaign also ended quickly as she was sent home after a 6-4 6-4 loss to Spain's Carla Suarez Navarro.
Russia's Maria Kirilenko, seeded 14th, managed to keep the draw on an even keel when she defeated American Vania King in straight sets.