World number three Serena Williams came through a big injury scare when she rolled her right ankle before reaching the Australian Open second round. The 15-time Grand Slam winner landed heavily and went to ground in the first set before gingerly going through the motions to beat Romanian Edina Gallovits-Hall 6-0, 6-0. Williams was comfortably winning 4-0 when she reached for a forehand in the fifth game and landed heavily, with her ankle twisting. The 31-year-old tumbled over with her hands over her face. A trainer rushed on court and she was helped to her chair for a medical timeout where her strapping was replaced. She returned to close out the set but was clearly in pain and her movement was affected as she received more treatment at the changeovers. Despite the injury, the imposing Williams was far too good for Gallovits-Hall who failed to take advantage, allowing her opponent to wrap up the match in just 54 minutes while keeping her movements to the minimum. Fresh from claiming her 47th career title in Brisbane and with a rare calendar-year Grand Slam in her sights, the American is the hot favourite in Melbourne. Williams, who won Wimbledon, the US Open and Olympic gold last year, is halfway to holding all the major titles at once for the second time, after first completing the non-calendar year \"Serena Slam\" in 2002-2003. She also raised the stakes when she said in Brisbane that she was \"absolutely\" eyeing a Grand Slam of all four major titles this year, which was last achieved by Steffi Graf in 1988. Williams won the tournament in 2003, 2005, 2007, 2009 and 2010, and another Australian tournament victory would return her to world number one. From AFP