MELBOURNE, Australia -- Serena Williams held out her palms as if pleading to the heavens, trying to figure out why nothing was going right.

She talked to herself, talked to her racket, and still she whacked balls into the net as though her arms had inexplicably lost all their strength.

	Elena Likhovtseva will battle 10th seed Conchita Martinez in the quarterfinals.

The 18-year-old U.S. Open champion sank in a sea of errors Monday at the Australian Open, going down in straight sets in the fourth round against Elena Likhovtseva.

Williams, who had looked so sharp in her previous victory, could barely control the ball in a 6-3, 6-3 loss replete with 32 unforced errors -- a dozen more than the No. 16 Likhovtseva.

"I couldn't make any shots ... I couldn't do anything," said the third-seeded Williams, who came into the Australian Open after not playing a match in three months. "There's no excuse for me to have lost this match. I just couldn't find my rhythm throughout the whole match.

"I don't know why I made so many errors. I just didn't do anything right."

Williams refuted suggestions that she was unprepared for the Australian Open after coming here from Florida just a few days before the tournament.

"I was here long enough," she insisted. "That's no excuse."

No. 1 Martina Hingis had to come back from 0-3 in the second set to beat No. 12 Sandrine Testud 6-1, 7-6 (3). Hingis won 20 of the last 22 points in the first set before her brief lapse.

Hingis, who now has won 25 consecutive matches at Australian Opens, said she was sorry to see Williams out.

"I thought I would have a good chance to beat her right here, right now, especially because it has been my tournament for the last three years. I haven't lost here yet," Hingis said. "You always want to compete against the best."

Unlike her net-charging style earlier and in her U.S. Open title run last September, Williams rarely attempted to attack against the Russian baseliner. On the few occasions when Williams did rush the net, she succeeded, but then she backed off again in futile attempts to win with groundstrokes.

Williams led 3-1 in the first set, but slapped 10 backhands into the net in losing the next five games. In all, Williams had 17 backhand errors to just six by Likhovtseva.

Williams fell behind 3-0 in the second set, but rallied back to 3-3, only to see Likhovtseva sweep the last three games. Williams gave Likhovtseva the first of her three match points with a backhand into the net, then dumped another backhand into the net on the final point.

The victory gave Likhovtseva, 24, the first Grand Slam quarterfinal berth of her career. It was also her her first win over Williams in three career meetings.

Likhovtseva will battle 10th seed Conchita Martinez of Spain in the quarters. Martinez was a 6-1, 6-1 victor over American Kristina Brandi.

Also reaching the women's quarterfinals was No. 13 Arantxa Sanchez-Vicario, who beat No. 6 Barbara Schett 1-6, 6-0, 7-5.