WIMBLEDON, England ? It was enough to draw double-takes.

Was that really Andre Agassi charging the net the way a classic grass-courter would? Serve-and-volleying as if he’d done it all his life? And winning the points?

It sure was. Hey, this is one ol’ guy quite capable of new tricks.

Adding a wrinkle — to his game, we mean — the 33-year-old Agassi moved a step closer to becoming the oldest Wimbledon champion in the Open era by beating Younes El Aynaoui 5-7, 6-4, 7-6 (4), 7-6 (4) Saturday to reach the fourth round.

Agassi won the point all 10 times he came in behind his serve, and he was 27-for-30 overall at the net.

“I don’t know what got into me out there,” Agassi said, smiling. “I probably won’t do that again until about 2010.”

The first of his eight Grand Slam titles came at the All England Club in 1992, and he could break the Wimbledon record for biggest gap between championships (Bill Tilden won the tournament in 1921 and 1930).

First things first, though.

Agassi’s opponent in the round of 16 will be Mark Philippoussis, a three-time quarterfinalist. The 6-foot-4 Philippoussis can pound serves with the best of ’em, and he compiled 33 aces in beating Radek Stepanek 4-6, 7-6 (7), 6-4, 7-6 (6). The 1998 U.S. Open runner-up was broken once — in the opening game, when he double-faulted twice.

Also into the fourth round: No. 10 Tim Henman, the lone Briton left; 2002 finalist David Nalbandian; French Open champion Juan Carlos Ferrero; and No. 13 Sebastien Grosjean. Henman faces Nalbandian next. Two seeded players lost: Alexander Popp beat No. 11 Jiri Novak, while Olivier Rochus defeated No. 30 Jarkko Nieminen.

Philippoussis is unseeded after a string of left knee operations.

“I’ve never doubted my ability,” he said. “I’ve always said, ‘If I’m healthy, I’m dangerous.”‘

That’s also the case with two-time major champion Mary Pierce, who has had back, shoulder, abdominal, ankle and groin problems since winning the 2000 French Open. Now in better condition, Pierce reached Wimbledon’s fourth round for the first time since 1999 by topping No. 23 Lisa Raymond 4-6, 6-3, 7-5.

Also advancing: defending champion Serena Williams, French Open champion Justine Henin-Hardenne and Jennifer Capriati. Maria Sharapova knocked off No. 11 Jelena Dokic 6-4, 6-4 to become the fourth wild-card entry ever in the fourth round.

Agassi, at this stage of a major for the 37th time, built his career from the baseline. As he said before Wimbledon: “If I need my volleys to come through for me to win a match, then I’m hoping for a lot out there.”

Yet there he was on Centre Court against the 27th-seeded El Aynaoui, serve-and-volleying to end the match’s seventh game. He did it again for the last point of the ninth game. He did it, mainly, to counteract El Aynaoui’s slice backhand, which slows points and gives the Moroccan a chance to set up his big forehand.

“I wanted him to feel that he can’t just get away with something floating up there,” Agassi said. “I wasn’t going to play a match where I have to constantly execute, while he just sort of hacks it around.”

Agassi prides himself on fitness, but the 31-year-old El Aynaoui is no slouch, either. After all, he hung in there with Andy Roddick — a player 11 years his junior — in a 5-hour Australian Open quarterfinal with a 21-19 fifth set.

Still, late in the fourth set, after more than 3 hours under the sun, Agassi was the fresher man, and he sprinkled drop shots to fluster the tiring El Aynaoui. When El Aynaoui put a forehand in the net to give Agassi a 5-4 lead in the final tiebreaker, the Moroccan chopped his racket on the court, then walked over and flung it into the third row of the stands, where a fan caught a souvenir.

Two points later, Agassi’s final serve of the day was his fastest, 123 mph, and it set up a forehand winner.

Agassi is the tournament’s oldest entrant, the oldest man to be ranked No. 1, and he’s tied for the tour lead with four titles in 2003.