RAFAEL NADAL found his latest win at the French Open so taxing that he took a seat in the middle of a game and called for a doctor.

The problem apparently involved a bite of banana and wasn't serious. A bigger issue for Nadal was Frenchman Paul Henri-Mathieu, who traded groundstrokes with the defending champion for four hours, 53 minutes before losing in the third round yesterday, 5-7, 6-4, 6-4, 6-4.

Among Nadal's record 56 consecutive clay-court wins, the latest ranked with the most memorable - and it came on his 20th birthday. The epic first set alone lasted one hour, 33 minutes, and one game took 15 minutes.

A stadium filled with partisan Parisians hung on every point, rooting for an upset. Instead, Nadal improved to 10-0 at Roland Garros and remained on course for a much-anticipated showdown in next Sunday's final against top-ranked Roger Federer.

The match included a curious interruption at a pivotal moment, with Nadal serving for the third set at 5-4, 15-all. He hurriedly took a seat in his changeover chair, waved a banana peel at the chair umpire and pointed to his throat, as though the food he'd eaten during a changeover was stuck there.

ANXIOUS

Appearing anxious, Nadal conferred with a trainer and a doctor, then resumed play and closed out the set four points later to take the lead for good.

Even in the final set, the grinding nature of the rallies never slackened - the first game took 10 minutes. The wear of the match will make Nadal's fitness an issue in the fourth round tomorrow against two-time Grand Slam winner Lleyton Hewitt.

Also advancing were six players who earned fourth-round berths at a Grand Slam event for the first time - Shahar Peer, Anna-Lena Groenefeld, Alberto Martin, Julien Benneteau, Ruben Ramirez Hidalgo and Novak Djokovic.

The 19-year-old Peer became the first Israeli woman to reach the round of 16 at a Grand Slam event since Anna Smashnova did it at the French Open in 1998. Seeded 31st, Peer advanced by upsetting 2004 runner-up Elena Dementieva 6-4, 7-5.

"We have maybe four clay courts in Israel," Peer said. "The rest is just hard courts. But I think the way I play and the way I move, I can improve and play better and better on clay."

OTHER ADVANCERS

Others advancing included defending champion Justine Henin-Hardenne, whose opponent today will be 2004 winner Anastasia Myskina.

No. 12 Martina Hingis, playing at Roland Garros for the first time since 2001, and No. 2 Kim Clijsters also won. No. 32 Gisela Dulko beat Shenay Perry 6-1, 6-1 in 52 minutes, leaving one American - Venus Williams - in the women's draw.

Mathieu, seeded 29th, didn't figure to give Nadal much of a test. The slender Frenchman had lost all four of their previous matches, including two this year, and had won only one of his past 15 matches against top-10 opponents.

Perhaps his biggest claim to fame is that he's the last player to beat Pete Sampras - at Long Island in 2002.

But Mathieu played Nadal on even terms from the baseline, winning his share of long rallies, and came forward enough to keep the Spaniard on the defensive. Mathieu won 36 points at the net to seven for Nadal.

Nadal lost his serve six times and converted only eight of 29 break-point chances. But inexhaustible as ever, he kept scrapping.

On one point the crowd thought Mathieu had hit a winner and erupted, but Nadal scrambled to scoop the ball back and went on to win the rally.

In the third set, the Spaniard yanked a running forehand passing shot crosscourt from five steps behind the baseline for a winner. He then hopped across the court and threw a jubilant uppercut.