Andre Agassi, Andy Roddick and Lindsay Davenport kept the stars and stripes flying high above Melbourne Park on Sunday with a trio of sizzling performances in the Australian Open fourth round.

Defending champion Agassi blazed a trail into the quarter-finals, blasting away Thailand's Paradorn Srichaphan 7-6, 6-3, 6-4.

He was swiftly joined by top seed Andy Roddick who made beating Dutchman Sjeng Schalken look as easy as 1-2-3 -- triumphing 6-1, 6-2, 6-3.

Women's fifth seed Davenport was just as emphatic, beating 11th seed Vera Zvonareva 6-1, 6-3, a thrashing that left the Russian in tears.

Davenport will play Justine Henin-Hardenne next after the top seed remained on track for a first Australian Open crown with an economical 6-1, 7-6 defeat of unorthodox Italian Mara Santangelo.

France's fourth seed Amelie Mauresmo also advanced, made to fight all the way before beating brave local hope Alicia Molik 7-5, 7-5.

Agassi recovered from an early loss of serve to win the first set against Paradorn and never looked back.

"I could have blown the first set open a lot sooner, I had my chances...but I think I did everything pretty well today," said the four-times champion.

"EXECUTING EVERYTHING"

"I had to be executing everything pretty well. Against Paradorn I am much better if I am doing everything well and nothing spectacular. You can't give him a lot of looks."

Agassi will meet Sebastien Grosjean for a place in the semis after the Frenchman beat American Robby Ginepri 6-4, 3-6, 6-4, 6-1.

Roddick followed Agassi on to Rod Laver Arena centre court and took just 79 minutes to wipe Schalken.

The Dutchman simply had no answer to Roddick's power off the ground or pace of serve.

"I feel solid out there -- it's all right," the 21-year-old American said. "I thought I returned really well, from the back of the court that's as well as I've played this tournament."

Roddick will next face former world number one Marat Safin after the Russian overpowered American James Blake 7-6, 6-3, 6-7, 6-3.

The match featured a spectacular shot from Safin to break Blake a final time when the Russian appeared to throw the racket at the ball -- an illegal shot.

Blake refused to blame that one point for the defeat.

Safin said: "It was just pure luck, 100 percent. I think I just threw it...I don't know how it happened."

Whether the racket was in his hand when the ball was struck or not was too close to call for the umpire to make and the break stood.

The fierce-hitting Russian, who has slipped to 86th in the world after an injury-plagued 2003, was a finalist here in 2002 and was the 2000 U.S. Open champion. Tuesday's match with Roddick falls on Safin's 24th birthday.

Henin-Hardenne's far from emphatic win over little-known qualifier Santangelo lines her up for a tough last-eight showdown with Davenport, the only former champion still in the draw.

The Belgian, holder of the French and U.S. Open titles, is a strong favourite to win her first Australian Open but did not have things all her own way against an opponent ranked 129th in the world.

"It wasn't an easy match. It was a big fight in the second set. She played a good match," Henin-Hardenne said. "She had nothing to lose."

"FEELING GOOD"

Henin-Hardenne will have to be in much better form against 2000 champion Davenport.

On Sunday the American's heavy hitting overpowered 19-year-old Zvonareva from the start. Such was Davenport's dominance that the match lasted just 47 minutes.

"I've had a lot of tough matches with her in the past...I really didn't expect it to be like that," said Davenport who showed no sign of the foot injury which hampered her last year.

"I'm feeling great right now. Excited to be back in the quarters, feeling healthy. The foot is feeling good."

Mauresmo, a finalist at Melbourne Park in 1999, was made to work for every point in her fourth round match before finally putting down Molik's challenge.

"She gave me a lot of problems. You guys must be a little disappointed," Mauresmo told the crowd. "But I just really wanted to get through this one and get to the quarters."

Mauresmo will play 32nd seed Fabiola Zuluaga of Colombia for a place in the semis.