World No. 1 Lindsay Davenport needed just 57 minutes to earn a quarterfinal berth at the U.S. Open on Monday, while seventh seed Justine Henin-Hardenne was bounded in straight sets by France's Mary Pierce. Davenport disposed of 15th seed Nathalie Dechy 6-0, 6-3 in fourth-round action. The second-seeded Davenport, a three-time Grand Slam champ, will next face sixth-seeded Russian Elena Dementieva, who defeated 11th seed Patty Schnyder of Switzerland, 6-4, 6-3. Pierce, the 12th seed, won the first five games of her match with Henin- Hardenne and then held off her Belgian opponent, 6-3, 6-4. That set up a quarterfinal encounter against France's Amelie Mauresmo, the third seed, as she upended 19th seed Elena Likhovtseva of Russia, 6-1, 6-4. Davenport's last major title come at the 2000 Australian Open. The American captured the U.S. Open back in 1998 and was the "Big Apple" runner-up in 2000. The 29-year-old Davenport was the runner-up at the Aussie Open and Wimbledon earlier this year, but has been hampered with a back injury. However, she is fresh off a hardcourt title in New Haven and just regained the No. 1 ranking after losing it briefly to Russian Maria Sharapova -- the tourney's top seed. Davenport moved to 8-0 all-time against Dechy and reached her 29th career Grand Slam quarterfinal. "Today was the best match I've played since Wimbledon," Davenport said. "It's the kind of tennis I want to play. Now what happens on Wednesday, I have no idea." Dementieva, last year's runner-up at the U.S. Open, took advantage of 37 unforced errors from Schnyder and moved to a matchup against a woman she has struggled against. Dementieva is 4-10 all-time against Davenport. "With Lindsay, it looks like she's in a great shape," Dementieva said. "It's just amazing how quick she can recover from her injury. But at the same time, I feel like I have nothing to lose." Mauresmo moved to 7-1 all-time against Likhovtseva and has reached at least the quarterfinals at the U.S. Open five straight years. "I'm just taking it very in a very relaxed way this year here at the U.S. Open," Mauresmo said. "Just the way I think I was at Wimbledon. I'm trying to keep that momentum going." Mauresmo reached the semifinals at Wimbledon this year before losing to Davenport in three sets. Pierce won the first five games of her match during the night session and then had to fight off Henin-Hardenne, the 2003 U.S. Open titlist, down the stretch to defeat her opponent for the first time in five career matches. It was sweet revenge for Pierce, who was crushed by Henin-Hardenne, 6-1, 6-1 in the final of this year's French Open. It won't get any easier for Pierce, as she is 2-4 against Mauresmo and has lost to her compatriot four straight times. This is Pierce's 13th appearance in the U.S. Open main draw. She reached her third quarterfinal at the event. The 2005 champion will earn at least $1.1 million.