Melbourne, Australia ? Serena Williams won her eighth and most improbable Grand Slam title, overwhelming top-seeded Maria Sharapova, 6-1, 6-2, today in the Australian Open.

Only the second unseeded woman to win the Australian title in the Open era, Williams came into the tournament ranked No. 81 after spending most of last season on the sidelines because of a knee injury.

“I’m really enjoying this,” said Williams, who will jump to No. 14 next week.

It was her first title in 15 tournaments since winning the 2005 Australian Open and the most dominating win in a completed championship match at Melbourne Park since Steffi Graf beat Arantxa Sanchez-Vicario, 6-0, 6-2, in 1994.

Williams finished off Sharapova with a backhand winner, then threw her racket in the air and dropped onto her back on the court.

The 25-year-old American, also the 2003 champion, got up and skipped over to the side of the court, swapping high-fives with mother Oracene Price and other people in the stands before jogging back onto court with her arms up in triumph.

Serving for the match, Williams fired two aces to earn triple-match point, then finished it off in 1 hour, 3 minutes with the backhand winner.

In the men’s final Sunday, top-ranked Roger Federer is aiming for a 10th major title against Grand Slam final newcomer Fernando Gonzalez. Gonzalez overpowered Tommy Haas, 6-1, 6-3, 6-1, in the semifinals Friday, a night after Federer beat No. 6 Andy Roddick, 6-4, 6-0, 6-2.