MELBOURNE, Australia -- Top seed Pete Sampras of the United States continued defense of his Australian Open crown Friday by disposing of Sweden's Magnus Gustafsson.
On the women's side, Americans Lindsay Davenport and Venus Williams posted straight-set victories to advance to the fourth round, but fourth seed and reigning French Open champion Iva Majoli of Croatia was stunned by 44th-ranked Tamarine Tanasugarn of Thailand, 6-0, 6-2.
Two days after sweating out a three-set victory over Slovakia's Karina Habsudova, Davenport, the second seed stormed past Italy's Flora Perfetti, 6-2, 6-2 to advance to the fourth round for the fifth straight year. Williams, who defeated younger sister Serena in the second round, knocked off another talented teen in 18-year-old Amelie Mauresmo of France, 6-1, 6-4.
Sampras, who improved to 33-5 lifetime at the Australian Open, fired 18 aces and won 83 percent of the points on his first serve. He broke the Swede's serve three times and won 96 points to Gustafsson's 79.
"For the most part it was a pretty solid day," Sampras said. "I didn't play great, but I thought I played pretty solid. I served well enough not to get my serve broken. I have no complaints about the way my performance is progressing so far, and in the future things are looking real smooth."
Sampras will face Hicham Arazi of Morocco in the fourth round. Arazi, ranked 47th in the world, outlasted Francisco Clavet of Spain, 4-6, 6-4, 3-6, 6-2, 6-1.
The 27-year-old Sampras finished 1997 as the top-ranked player in the world for a record-tying fifth straight season. He has won 10 career Grand Slam titles and can match Rod Laver and Bjorn Borg with 11 while moving within one of Roy Emerson's record of 12 should he capture his third Australian Open title.
The 31-year-old Gustafsson, playing in the third round of a Grand Slam event for the first time since Wimbledon in 1996, fell to 0-8 lifetime against No. 1 players.
Davenport, who improved to 19-5 lifetime in Melbourne, broke Perfetti's serve six times during the one-hour match as she defeated her Italian opponent for the second straight year at this event. She downed Perfetti in the second round in 1997.
"I don't quite feel i am playing as well as i did at the end of last year, but I'm getting better as the tournament goes on," Davenport said. "The conditions haven't been too bad yet so I don't feel like anything has been taken out of me, but tough matches can be good. When you pull through, sometimes the pressure is lifted off your back."
The 17-year-old Williams, the U.S. Open finalist, broke Mauresmo six times, but lost her own serve three times. Mauresmo committed 40 unforced errors and was unable to capitalize on a chance to go up 5-2 in the second set.
"She shouldn't have had the lead," Williams said. "I just made a heap of mistakes, played lackadaisical for quite a few games, just making mistakes for no reason."
Williams will face Switzerland's Patty Shnyder in the fourth round, with Davenport looming in the quarterfinals. Schnyder outlasted No. 13 Lisa Raymond of the United States, 2-6, 6-3, 8-6, to reach the fourth round for the second straight year.
The 20-year-old Tanasugarn had never advanced past the third round in a Grand Slam tournament. She has reached one career WTA Tour final -- in Pattaya, Thailand in 1996 -- and participated in the first match played at Arthur Ashe Stadium at last year's U.S. Open, defeating Chanda Rubin.
"Last night I was thinking I would just try to play my best tennis and it's a good opportunity if I win because it would be the first time I beat a top-10 player," Tanasugarn said. "It wasn't her day today. She was missing a lot and I was just trying to put the ball in court and play my best tennis. I never thought I had a chance, even at 5-1, because I know Iva's going to fight back and try for every ball."
Majoli committed 33 unforced errors, double-faulted seven times and won just 34 percent of points on her first serve.
"I think I'm the most shocked person, because i was feeling great and practiced really hard before coming into this tournament," Majoli said. "I was playing well and feeling well, and a thing like this happens. I was focused, I went to sleep early, and I came to the court and couldn't find my timing. I don't know."
Two other women's seeds emerged victorious in their third-round matches. No. 9 Sandrine Testud of France dispatched Adriana Gersi of the Czech Republic, 6-4, 6-2, and No. 15 Ruxandra Dragomir of Romania earned a fourth-round date with Davenport by downing Florencia Labat of Argentina, 6-2, 7-5.
Eighth seed Conchita Martinez of Spain also advanced to the fourth round, outlasting France's Anne-Gaelle Sidot, 3-6, 6-0, 6-3.
For the men, fourth seed Jonas Bjorkman of Sweden, who was pushed to five sets by Wayne Ferreira on Wednesday, had an easier time with Frenchman Fabrice Santoro, prevailing, 7-5, 6-3, 6-4.
Also, sixth seed Petr Korda of the Czech Republic celebrated his 30th birthday with a 6-2, 7-6 (10-8), 6-2 victory over American Vincent Spadea, but Alex Corretja of Spain became the 10th men's seed to get knocked out as Frenchman Cedric Pioline ousted the 11th seed, 6-2, 6-1, 6-4.