Andy Roddick overcame some frustrating lapses before advancing to the Australian Open quarterfinals with a 6-3, 7-6 (6), 6-1 win Monday over Germany's Philipp Kohlschreiber.
Top-ranked Lindsay Davenport breezed into the women's quarterfinals without any major problems, but third-seeded Anastasia Myskina, the French Open champion, and fellow Russian Elena Dementieva were eliminated.
Davenport needed just an hour to beat No. 13 Karolina Sprem 6-2, 6-2. Sprem held serve only once in each set, while Davenport converted six of her 10 breakpoint opportunities.
Roddick lost just three points on his serve in the first set, but was more erratic in the second, doubling his number of unforced errors to 12 and throwing his racket to the court after sending a forehand long.
After taking the tiebreaker on consecutive errors by the 102nd-ranked Kohlschreiber, Roddick dominated the third set, breaking the German twice.
"I don't think I hit the ball as clean as I did in the first three matches," the second-ranked Roddick said. "I just felt like I was fighting it a little bit more.
Roddick next faces Russia's Nikolay Davydenko, who defeated Guillermo Canas of Argentina, 6-3, 6-4, 6-3. No. 3-ranked Lleyton Hewitt, a potential semifinal opponent for Roddick, was playing Spain's Rafael Nadal in a fourth-round match Monday.
The two remaining Argentinians in the men's draw, No. 6 Guillermo Coria and No. 9 David Nalbandian, were playing the last match on center court.
At times, Roddick lacked intensity against the lowest-ranked man remaining in the draw, relying on his big serve for motivation. He served 15 aces, many just when games were looking stale.
Myskina sprayed forehands wide and long, and finished with 45 unforced errors, losing 6-4, 6-2 to 19th-seeded Nathalie Dechy.
She was so concerned about her faltering forehand in the second set that she ran around to hit a double-fisted backhand on a net approach to get one break of serve back.
She shanked a forehand to give Dechy match point and dumped another into the net to finish it.
"I couldn't focus during the match, I lost a lot of easy balls," Myskina said. "I think I have to forget this match."
Dementieva led 12th-seeded Patty Schnyder by a set and two breaks before losing 6-7 (6), 7-6 (4), 6-2.
Dementieva had 61 of the 116 unforced errors in her match. She saved a match point with a convincing forehand winner but then gave Schnyder another with a double fault and lost the match when she dumped a forehand into the net.
Schnyder was a semifinalist here last year, beating three seeded players in straight sets before losing to eventual runner-up Kim Clijsters in the next-to-last round.
The 25-year-old Dechy is in the quarterfinals of a Grand Slam for the first time since making her debut in 1995 and said her run proved "it's never too late."
The only Russians remaining in the women's draw are Grand Slam champions, and they're playing each other in the quarterfinals. US Open champion Svetlana Kuznetsova beat fellow Russian Vera Douchevina on Sunday and next plays Wimbledon winner Maria Sharapova.