WIMBLEDON, England -- Last year, when three baseliners wandered into the semifinals at the All England Club, people wondered if they had slowed down the fabled grass.

	Andre Agassi is one of the best returners in the game, yet he still couldn't stop Mark Philippoussis.

No one is asking that question this year.

For the first time in 117 Wimbledon tournaments, players aren't obligated to show deference to the Royal Box, but on Monday, serves ruled again.

Mark Philippoussis stroked 46 aces -- tying a Wimbledon record and three shy of the all-time Grand Slam record -- in a dramatic come-from-behind 6-3, 2-6, 6-7 (4), 6-3, 6-4 victory over No. 2 seed Andre Agassi.

Andy Roddick, the No. 5 seed, who has won 62 of his 64 service games here, took out Paradorn Srichaphan 6-4, 3-6, 6-3, 6-2.

Thus, Roddick and Philippoussis reached the quarterfinals and stand a reasonable chance to meet in the championship final.

"I had a chance at 2-4 in the fourth," Agassi said later, breaking it down. "I had him love-40. He made five first serves. Not much I could have done there. I think I only got one in play.

"In the fifth, I had three break points at three-all. One of them, second serve, he hit 120 miles an hour."

Originally, Philippoussis was credited with equaling the existing Wimbledon record of 46 aces by Goran Ivanisevic in a 1997 match. But there was a discrepancy between the IBM computer statistics and the official scorecard for Philippoussis' match, which recorded 45 aces. After tournament officials reviewed the tape, the number was confirmed to be 46. Philippoussis is 10-0 in his career when he serves 30 aces or more.

Philippoussis stopped short of saying it was the match of his career, but allowed, "It's definitely up there. It was extremely important for me."

The middle Monday of Wimbledon is probably the best day in all of tennis. All eight round of 16 matches, on both the men's and women's sides, are played and the action is furious. The story of this frenetic day was Philippoussis, the Australian who has suffered through three surgeries on his left knee in the last year.

He came into the tournament ranked No. 51 in the world, but he was once as high as No. 8 and had reached the quarterfinals here on three previous occasions. In 1999, he actually won the first set against Pete Sampras but was forced to retire when the cartilage in his left knee couldn't handle the strain of the moment.

Healthy again, Philippoussis has seen his game flower. He reached the final in Scottsdale, losing to Lleyton Hewitt in the final. Agassi knocked him out in the round of 16 at Miami (his second loss to Agassi), and Guillermo Coria ended his run at Hamburg in the quarters. Still, after a first round loss to Richard Krajicek three weeks ago at Queen's, there were questions about Philippoussis' mindset.

He answered them with three straight victories, the last an inspired effort over Radek Stepanek. Philippoussis trailed by a set and was down 0-4 in the second-set tiebreaker. Philippoussis had already struck 73 aces in the tournament when he lined up opposite Agassi, who along with fellow Aussie Hewitt is one of the game's best returners of serve.

It was upon the axis of Philippoussis' serve that the match spun. Agassi did not disappoint on that count, leaning outside on numerous occasions and steering some astonishing returns past Philippoussis, who served and volleyed on 92 of 94 service points.

In the end, however, it came down to the eighth game of the ultimate set. Philippoussis broke Agassi in the seventh when the American inexplicably tossed off four errant backhands. Serving at 4-3, Agassi had several chances to level the match. On his first break point, Philippoussis stung a serve down the middle that nicked the frame of Agassi's racket. Two deuces later, Philippoussis ripped another ace down the middle and, finally, an ace outside for a 5-3 lead.

Match point, appropriately, was an unreturnable serve, one of a staggering 79. More than half of Philippoussis' serves did not come back. And so, after six consecutive losses to Agassi, Philippoussis was finally a winner.

Philippoussis had 21 break points and converted three. Agassi earned 11 break points and broke through only twice. Only Richard Krajicek, who had 49 aces in a 1999 U.S. Open quarterfinal match, surpassed Philippoussis' effort in a Grand Slam.

"There's nothing to get too excited about," Philippoussis said, unconvincingly. "It's the quarterfinals. I have a match (versus Germany's Alexander Popp) to concentrate on. The good thing is I've been in the quarterfinals a few times. That definitely helps with experience."

While Agassi was relegated to Court 1, it was Roddick who was featured on Centre Court. He only served a relatively meager 14 aces but controlled the match. He broke Srichaphan in the fifth game and, aside from a lapse in the second set, looked confident and comfortable.

It was the deepest penetration here for Roddick, who was knocked out in the third round in his two previous appearances. He has now won nine matches in a row, going back to his title at Queen's.

Roddick, usually a power baseliner, has seen his game become more diverse under new coach Brad Gilbert. Roddick actually made a point of approaching net to disturb Srichaphan's rhythm and won 24 of 29 points there.

"He's a big, strong guy," Roddick said. "Even when I try to bully him to one of the corners, he can still come up with good shots of his own. It's definitely something I tried to do the more the match went on."

Roddick next faces Jonas Bjorkman -- a 6-4, 3-6, 6-3, 7-6 (4) winner over Max Mirnyi -- in Wednesday's quarterfinals.

Even though Agassi insisted that this wasn't his last match at Wimbledon, there was the acute sense of a torch passing. He is 33 and this was his 13th Wimbledon. Roddick, 20, was only 9 years old growing up in Austin, Texas, when Agassi won his first (and only) Wimbledon trophy.

When Agassi won the Australian Open back in January, it partially obscured the fact that Roddick had his best Grand Slam effort ever, reaching the semifinals before losing to Rainer Schuettler.

And now he is the last American man left in the draw.

"Little weird, huh?" Roddick asked.

He was asked about the pressure of being the man on his home turf in the United States.

"See, I've never been the man in the U.S.," Roddick answered. "There's always been a couple guys named Pete and Andre. So I really wouldn't know."

That might be about to change.

Greg Garber is a senior writer at ESPN.com.