Martin played nearly flawlessly in the first set, but Sampras fought back and saved two set points in the third before prevailing 3-6, 6-4, 7-5, 4-6, 6-2 in three hours, 20 minutes.
Also struggling was Monica Seles, the co-top women's seed who survived a second-set scare in a 6-2, 7-5 victory over Belgium's Sabine Appelmans.
To whistles and jeers, 12th-seeded Mary Pierce of France became the first women's seed to be eliminated. She lost to Barbara Rittner 6-4, 6-2. The eighth-seeded Brenda Schultz-McCarthy of the Netherlands was defeated by Irina Spirlea of Romania 6-3, 3-6, 6-2.
Fourth-seeded Arantxa Sanchez Vicario cruised into the fourth round, defeating Russia's Elena Likhovtseva 6-0, 6-0 in 53 minutes. Also advancing were sixth-seeded Anke Huber of Germany, who beat Sarah Pitkowski of France 6-2, 6-2.
No. 10 Jana Novotna defeated Elena Makarova of Russia 6-1, 7-5. And No. 13 Magdalena Maleeva of Bulgaria was a 6-2, 6-1 winner over Miriam Oremans of the Netherlands.
On the men's side, No. 6 Yevgeny Kafelnikov of Russia was the first to reach the fourth round, downing Felix Mantilla of Spain 6-4, 6-2, 6-2, in one hour, 51 minutes.
Richard Krajicek, No. 13 of the Netherlands beat Australian Todd Woodbridge 7-5, 6-2, 6-2. Chris Woodruff, the unseeded American who shot down fourth-seeded Andre Agassi in the second round, lost in a grueling match with Jonas Bjorkman of Sweden 7-6 (7-5), 2-6, 4-6, 7-5, 6-4. Unseeded French player Guy Forget was trounced by Francisco Clavet of Spain, 6-3, 7-5, 6-3.
Seventh-seeded Jim Courier was matched with Karol Kucera of Slovakia.
After three days of warm, sometimes hot sunny weather that favors attacking serve-and-volley players, conditions changed dramatically Thursday, which was cooler and often overcast.
After a 25-minute first set, Sampras and Martin held even in the second until Sampras broke for 5-4, then served out the set.
In the third, Sampras saved two set points in the 10th game after two double faults and going down 15-40 on a serve. Martin had two set points, but Sampras saved both of those to hold for 5-5, then broke in the next game for 6-5 and served out the set.
Sampras looked tired in the fourth set and Martin broke him in the 10th game. Sampras saved two set points with aces, but Martin converted the third with a backhand return down the line.
Regaining his form in the final set, Sampras broke serve in the third game for a 2-1 lead and broke again in the seventh game for a 5-2 lead. He ended the match with his 19th ace, to Martin's 29.
Seles, who had no problems in her first set against Applemans, fell behind early in the second.
Applemans went ahead 4-1, but then Seles won seven of the next eight games to close out the match. The Belgian dropped the final game at love, double-faulting on match point.
"I was distracted tremendously," Seles said. "I can't lose my concentration as I did in the second set."
For Pierce, it was her second early round Grand Slam exit this year after being knocked out of the Australian Open in the second round in January.
As Pierce raced off the court to a chorus of boos, the crowd cheered the unseeded Rittner of Germany, who had lost to Pierce on four previous occasions.
"I had a lot of pressure on me," said Pierce, a French Open finalist in 1994. "I made too many mistakes. They can cheer who they want to cheer for. "
(For other results, see Scorecard.)
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