As a three-time champion of the U.S. Open, Jimmy Connors has been involved in many classic tennis matches both here, at the National Tennis Center, and at Forest Hills. None, however, were likely any more dramatic than the victory he produced today.

Fighting off leg cramps, which he succumbed to moments after the match ended, twice down a service break in the fifth set, facing match game with his opponent serving, Connors fought past Andres Gomez of Ecuador, 6-7, 6-3, 6-1, 4-6, 7-6, winning the final tie breaker, 7-5.

This was not vintage Connors by any means. This was a very vulnerable Connors, his weak forehand and second serve exposed time and again by Gomez, a 6-foot-5, 21-year-old with an excellent forehand.

"I wouldn't want to make a living off that kind of match," said Connors, who spent almost an hour getting massages to alleviate the cramps and was still walking slowly afterwards. "We just went after each other. I kept waiting for him to stop slugging forehands in and slug a couple into the fence. He never did."

Connors' narrow escape overshadowed the most surprising upset on the men's side of the draw, Mike Cahill's 4-6, 6-2, 6-1, 6-4 victory over No. 12 seed Johan Kriek.

The shock in Cahill's victory is a double one: Kriek has always played well here, twice reaching the quarterfinals and last year the semifinals. Beyond that, Cahill, who now faces Connors, wasn't even in the draw originally. Only a last-minute no-show on opening day got him into the tournament. Now, Cahill, 29, is in the round of 16 here for the first time in his career.

There was one upset among the women, seventh-seeded Wendy Turnbull, once a finalist here, losing to Barbara Gerken, 7-5, 6-3.

Other seeded players were luckier, Bjorn Borg, Guillermo Vilas, Yannick Noah, Eliot Teltscher, Roscoe Tanner and Brian Gottfried winning among the men, and Martina Navratilova and Barbara Potter winning among the women.

Andrea Leand, who upset second-seeded Andrea Jaeger on Friday, proved to be no fluke as she advanced to the round of 16 with a 6-4, 6-3 victory over Julie Harrington.

But the match that enthralled the sellout crowd of 20,167 was Connors' 4-hour-23-minute duel with Gomez. Gomez's obscurity in the draw was illustrated when chair umpire Leon Lipp introduced him as being from Mexico when he took the court.

A few eyebrows were raised when Gomez won the first-set tie breaker, 7-4, smashing a gorgeous backhand down the line for the set. But Connors came back to win the next two sets easily and all appeared to be going according to the seedings.

"After the third set my legs began to cramp and I was very tired," Gomez said. "I thought I was in trouble but then in two minutes I was up, 3-1, in the fourth so I just said, 'Okay, let's go again.'"

By the fifth set, both men were exhausted.

After Gomez broke Connors in the third game of the fifth set, Connors' fighting instincts took over. Pumping himself up with his fist-shaking, head-tossing routine, Connors scrambled back. He got even at 3-all, twice coming in behind deep approach shots and watching Gomez hit his passing shots long.

"I had decided at that point that if he was going to beat me it would be with passing shots," Connors said. "I wasn't just going to stand back there and let him run into the bleachers to hit forehands."

Connors had two break points with Gomez serving at 3-4, but failed to convert them. On they went to 5-5. Serving at 30-40, Connors double-faulted to give Gomez the break and lead at 6-5. The murmur that spread through the crowd indicated that they thought Connors was finished.

Connors never gives up until he grudgingly shakes hands with a winner. He played an aggressive, all-out game, coming to the net on four of six points to break right back.

"I thought I might scare him a little if I came in," Connors said.

Gomez's inexperience began to show. He was sharp one point, tentative the next. And Connors was, in his words, "playing like a maniac."

With Connors leading, 3-2, in the final tie breaker, Gomez twice came up with big serves. Twice, Connors returned and Gomez made errors. On the first, he blew a sitter volley. On the second, Connors came in behind his return and Gomez lobbed deep. Connors led, 5-2.

Then Connors ran into an unexpected problem: his left hand began to cramp. He ran over and immersed it in the ice cooler. It worked a little but he double faulted on the next point and Gomez followed with a winner to make it 5-4.

The next point was the key. At one point Connors hit a forehand which Gomez thought was long. No call. Finally, Gomez punched a backhand beyond the base line and Connors led, 6-4. With the crowd screaming, Connors was at match point, but Gomez staved it off with a forehand winner.

Now Connors had the serve again, leading 6-5.

"I knew he would be looking for a serve up the middle to his backhand," Connors said. "I thought I would go wide, try for the ace and if I missed come back with a big kicker to his backhand. There was no reason to start playing safe at that point."

Connors stared, bounced the ball, tossed, grunted and slammed. The ball caught the corner of the service box for an ace, only his second of the day.

Gomez stared, the crowd screamed. Connors flung his arms into the air, leaned his head back and did a brief victory dance. Then he slammed the ball to the heavens and headed to a nearby box to fling his arms around his wife Patty.

"After all that work, after all that involvement," he said, "I thought I was entitled to show a little emotion. I dodged a bullet."