MELBOURNE, Australia — There were hundreds of reason why Serena Williams should not have won the Australian Open this year, and one reason why she did.

“God-given talent,” Oracene Price, Serena’s mother and coach, said about an hour after her daughter had defied not only odds, but logic, in winning her third Australian Open, 6–1, 6–2 over Maria Sharapova.

As much talent, and competitive spirit, as Williams has, even Price would not have expected this result. Not after Williams played 16 matches in 2006; not after she had failed to win a tournament since the Australian Open in 2005. As a civil suit accusing Williams, her father, and her sister Venus of reneging on a “Battle of the Sexes” exhibition match plodded along in a Florida courtroom last fall, Williams became depressed, and her motivation flagged. She missed many a practice session and gained weight quickly. In December, she trained for 10 days before flying to Tasmania for the Hobart International. When Price arrived from Los Angeles, she was shocked by her daughter’s condition.

“When I first saw her in Hobart, I was like, Oh my God,” Price said. “I said, have you been running? You haven’t been running. Do your sprints!”

Williams won two matches in Tasmania before losing to Sybille Bammer, a 26-year-old Austrian who was ranked 53 in the world, her highest ranking ever, at the end of 2006. She locked herself in her hotel room and had to be coaxed out by her mother’s e-mails.

To hear Williams tell it, that’s when her comeback began. She said she had a “Rocky moment,” in some park in Tasmania, alone with her exercise gear and no water. She ran. She did squats. She ran some more. “I was so mad I lost that match, I did like the ultimate workout, basically,” she said.

Though a few days running cannot return even the most gifted athlete to fitness, it seems to have done something more important for Williams: awaken her hunger to win. “I was really eager and famished, and I needed to feed,” she said.

She started terribly at the Australian Open, but once she reached the brink against Nadia Petrova, the no. 5 seed with the formidable strokes and frayed nerves, in the third round, her fortunes turned. Petrova served for the match and failed, and then the seeds began to drop as Williams gained confidence. In a span of two weeks, she had gone from a player with no chance to a champion, from 81 in the world to no. 14. She dedicated the victory to her half-sister Yetunde, who was shot to death in 2003.

The question now is, can Williams keep it up? Or are we going to have to wait a few years for her next rendition of “Rocky”? Williams went five majors without a title before she won here in 2005. She went seven before winning this one. Injuries, depression, lack of desire, and Hollywood distractions all played a role in her decline. Is it time, at last, for her to concentrate on tennis again?

Williams says it is, and she insists that she’s in better shape than some might believe. “Just because I have large bosoms and I have a big a**,” she said, laughing. “I’m just not built that way, I’m just bootylicious, so to say, and that’s just how it is.”

Price agrees that her daughter is fitter than she looks, but said there was room for improvement.

“She laughs at you guys when she hears you talking about how unfit she is,” Price said. “She laughs and says, Yeah, I know I’ve got to get fitter. I know I’m not fit, but it’ll get there.”

If she does, Williams could regain the no. 1 ranking and win several more majors. As this tournament showed, even a diminished Serena can win a major title among a field of women that has a surplus of forehands but, at the moment, a shortage of champions. There’s no telling what she might do at full strength. We won’t venture a guess, and neither would Price.

“I don’t predict things,” she said. “I don’t do things like that. Who can predict?”

With Serena Williams, no one can.