Melbourne: Serena Williams vowed to bounce back from her fourth-round exit at the Australian Open on Monday, but her loss to world number 56 Ekaterina Makarova suggests time may have caught up with the most dominant player of her generation.   

The 30-year-old played only two matches in the leadup before she was struck down with an ankle injury, and joked it was enough preparation for her bid for a 14th grand slam crown and sixth title at Melbourne Park.   

Heavily strapped and sedated with pain-killers, Williams moved strongly enough to mow through her first three opponents, but appeared listless and spent as she went down in a hail of unforced errors to the plucky Russian Makarova.   

Unable to scramble to her left side, Williams was picked off time and again by 23-year-old Makarova and opted to watch, rather than chase down, the winners fired off the Russian's backhand.   

Amid her frustrations, Williams's serve crumbled and she notched up seven double-faults, one of them conceding a decisive break in the second set that allowed Makarova to march to the brink of victory.   

"I served like a - I guess that's not appropriate," Williams told reporters. "I served ... I don't know. I can't even describe how I served, to be honest.   

"It wasn't good, though. My lefty serve is actually better than that. Maybe I should have started serving lefty."   

Williams is nothing if not a fighter and saved three match points with an ace and two booming serves, after saving five set points in the first set. But Makarova prevailed to become only the fifth player from outside the top 10 to beat Williams in a grand slam since 2000.   

Williams's two matches at the Brisbane International were her first tour clashes since she lost the U.S. Open final to Australia's Sam Stosur in September, following a sensational outburst at the chair umpire.   

At Brisbane she talked of being a lazy trainer, disliking sport and the athleticism required for it, but still arrived in Melbourne determined to compete and brushing off questions about her motivation.   

Look Forward   

Williams comes off an injury-ravaged year in which she failed to win a grand slam for the first time since 2006. Despite a five-month lay-off following the U.S. Open, the American was still unable to arrive in Melbourne injury-free.   

"No, no way," Williams answered when she was asked if she would have played at Melbourne were it not a grand slam.   

"I probably shouldn't have played. But no way.   

"Usually I play myself into the tournament," she added.   

"But I don't have a huge problem with an injury. So this is a completely different situation. So usually it's easier for me to play myself in because I'm usually physically okay."   

Despite her condition, Williams said she wanted to get back out on the practice courts and would play the United States' world group two match against Belarus in the Fed Cup in early February.   

"I look forward to our next match. I feel like I definitely can play so much better," she said of Makarova.   

"And that's good. Like if I felt like I couldn't play better, then that would be a problem.   

"I'm thinking already about practising as soon as tomorrow, you know, trying to figure - I can just think of a hundred things I can do.   

"So, like I said, it's a good thing I'm in that position as opposed to saying I couldn't do any better."