It was surprising enough that Martina Hingis exited the U.S. Open in the second round Thursday night. Even more stunning? Who beat her _ and how easily.

Hingis, the five-time Grand Slam champion back on tour after a three-year retirement, lost 6-2, 6-4 to 112th-ranked Virginie Razzano of France in the biggest upset of the tournament so far.

Hingis came into the day with a 44-14 mark this season, with none of the losses to anyone ranked lower than 23rd. Ten of her setbacks came against women who've won major championships.

``It's not only that she played well, but I didn't play good,'' Hingis said. ``I was a little flat and tired mentally. It just wasn't my day.''

Plus, it was the earliest U.S. Open defeat of Hingis' career; she won the 1997 title, reached two other finals here and never had lost before the fourth round. Razzano, in contrast, never has been past the third round at this or any other major. She began the week with a 9-17 record in 2006, including first-round losses at the French Open and Wimbledon.

``I played my game,'' said Razzano, who lost both of her previous matchups with Hingis in straight sets.

Toronto's Daniel Nestor and Bahamian partner Mark Knowles opened their doubles campaign by defeating Tomas Berdych and Jan Hajek of the Czech Republic 7-5, 6-3. Nestor and Knowles are seeded third.

About the only intrigue involved in the matches played earlier Thursday by Maria Sharapova and Lindsay Davenport was just how lopsided their victories would be. Serena Williams won in straight sets, too, although not before falling behind early. Fellow past champions Justine Henin-Hardenne and Svetlana Kuznetsova never were challenged.

Most of the buzz around the grounds focused on Thursday night's late match between Andre Agassi and eighth-seeded Marcos Baghdatis _ and what tennis was played in the afternoon didn't exactly thrill. So Agassi provided the day's signature moment without striking a ball: After a morning practice session, he autographed a teen's forehead with a marker, even making sure the final ``i'' was dotted.

Hingis aside, it was one 6-1 set after another for top women, or so it seemed. Well, not for Davenport: She beat Jelena Kostanic 6-0, 6-0, the first ``double bagel'' at the U.S. Open since 2002.

``These days don't happen that often, so you have to be happy when they come your way,'' said Davenport, who arrived in New York with right arm problems but hasn't shown any signs of distress. ``Some days, everything just seems to be working.''

That certainly was the case for champion Sharapova, who lost the first point of her match against Emilie Loit, then won 29 of the next 31 en route to a 6-0, 6-1 victory. Kuznetsova beat 16-year-old Lauren Albanese of the United States 6-1, 6-1, while Henin-Hardenne eliminated 17-year-old Vania King of the United States 6-1, 6-2. King's day wasn't done, however: She sang ``America the Beautiful'' before Hingis, then Agassi, played in the night session in Arthur Ashe Stadium.

Top-seeded Amelie Mauresmo had no trouble beating Meghann Shaughnessy of the United States 6-4, 6-3.

There weren't many tough tests in the men's draw, although No. 27-seeded Gael Monfils lost to Wesley Moodie, and two-time French Open champion Rafael Nadal dropped a set before getting past Luis Horna. Benjamin Becker _ no relation to Boris _ knocked off No. 30 Sebastien Grosjean 7-6 (3), 6-1, 6-2 and will face Agassi or Baghdatis.

Hingis, meanwhile, went from a tight match _ 2-2 in the first set _ to a blowout, losing seven games in a row to fall behind 6-2, 3-0. She broke serve to end that run, but Razzano broke right back, thanks to strong returns of Hingis' slow second serves.

Earlier, Sharapova traded in the Audrey Hepburn-inspired black cocktail dress-type outfit she wore under the lights Wednesday for a more traditional lavender number with what she called ``a little bit of that English, you know, bruncheon feel.''

She appeared to be out to lunch in the lone game she lost to Loit, double-faulting five times.

``I had a little bit of a choke game,'' Sharapova said.

Yeah, tell that to the 17th-seeded Daniela Hantuchova, who was dialed in with her flat, hard groundstrokes at the start of her match against Williams, aiming right at the lines with a high-risk style that was working. The approach forced Williams into the unusual position of playing defence, scrambling along a path several feet behind the baseline in a bid to merely extend points. It wasn't even close to working as Williams fell behind 5-2.

And then, serving for the first set at 5-3, Hantuchova simply fell apart, something she's done in the past at key stages of key matches.

This time, her collapse began with an ill-advised drop shot that bounced before it even got to the net. Then she tried another drop shot, with similar results. Then came one double-fault, and then another, allowing Williams her first service break and the start of a seven-game roll.

``She seemed to be a little nervous. It was definitely a big game,'' Williams said. ``At the same time, I hit some pretty big shots.''

Hantuchova beat Williams in January in the third round of the Australian Open, the last Grand Slam tournament the former No. 1 played before this one. Williams missed six months with a left knee injury, and for some mental healing, she's said. As a result, her ranking fell so far she needed a wild card to play in the Open.

``I don't really feel like an unseeded player, because I don't think about it,'' the seven-time major champion said. ``I don't know too many people that see Serena Williams next to their name and they're like, 'Yes!'''

Like plenty of tennis fans, Williams was planning to watch Agassi later Thursday.

``I love Andre. He's a great player. He reminds me a lot of me,'' Williams said, then caught herself. ``No,'' she said, ``the other way around.''