Lindsay Davenport and Justine Henin-Hardenne set up a quarterfinal clash with straight-set wins.
NEW YORK (AP) -- Gasping for breath after long exchanges, Serena Williams ran out of energy and answers against Amelie Mauresmo.
In a showdown between two women who've been ranked No. 1 and own a total of nine Grand Slam titles, the top-seeded Mauresmo won nine of the last 12 points Monday night to beat the unseeded Williams 6-4, 0-6, 6-2 and reach the U.S. Open quarterfinals.
"I could have came out on top had I made a few more shots and had I just been a little bit more consistent," said Williams, who didn't think her recent lack of matches was a factor. "Maybe a little bit more fire or something."
Williams, a seven-time major winner and 9-1 against Mauresmo coming in, was superb in the second set.
Turn during final set
But the outcome turned at 3-2 in the final set, when a 35-stroke exchange ended with Williams pushing a backhand into the net, then pausing for air -- something Mauresmo noticed.
That sent Mauresmo on her way to a key break, and Williams wouldn't win another game, saying later: "Just fell apart after that."
On match point, they engaged in a 24-stroke rally that Mauresmo ended with a sharply angled volley Williams couldn't get to in time.
"I don't think she picked up her game 1,000 percent or even that much," Williams said. "I just think that she cut back on the errors."
Now Mauresmo plays No. 12 Dinara Safina, whose path to the final eight hasn't included a seeded player.
The match under the lights at Arthur Ashe Stadium brought back some electricity to a tournament that felt a bit Monday afternoon like a party carrying on after the guest of honor has left. The U.S. Open did indeed proceed without Andre Agassi, although a fan cried out, "Do it for Andre!" during Andy Roddick's fourth-round match.
Roddick obliged, putting together a 6-3, 6-4, 6-3 victory over Benjamin Becker, the German qualifier who ended Agassi's career the day before.
Roddick and No. 5 James Blake, whose fourth-round match against No. 12 Tomas Berdych is Tuesday, are the only U.S. men left in the tournament. No. 18 Robby Ginepri bowed out with a 7-6 (1), 6-4, 3-6, 3-6, 7-6 (1) loss to No. 14 Tommy Haas.
Haas next faces 2000 Open champion Marat Safin, Safina's older brother.
Other past winners still in it are Lindsay Davenport and Justine Henin-Hardenne, who set up a quarterfinal clash with straight-set wins.
But 2004 Open champion Svetlana Kuznetsova is gone after losing to No. 19 Jelena Jankovic 6-7 (5) 6-3, 6-2. Also into the quarterfinals were No. 3 Maria Sharapova -- who lost the first three games before eliminating No. 24 Li Na of China 6-4, 6-2 -- along with 2004 runner-up Elena Dementieva.
Roddick won the 2003 Open but lost in the first round last year, part of a dismal stretch that briefly dropped him out of the top 10. Now he has Jimmy Connors as his coach and a 10-match winning streak.
"If you can't draw motivation from six months of bad results," Roddick said, "then you're not going to draw it from much."
His next foe is 2001 U.S. Open champion Lleyton Hewitt or No. 25 Richard Gasquet.
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