When Yannick Noah, seeded No. 13, looked at the draw sheet for the U.S. Open last week he thought he had a difficult first-round match: Robert Van't Hof, a young American who had beaten him the last time they played.

Then, Van't Hof withdrew and Noah breathed a sigh of relief when he was replaced by Andy Andrews, who had to play three qualifying matches just to reach the main draw.

"I thought I would have a fairly easy first round," Noah said today. "I had never heard of Andy Andrews. I think that's the first time I've played someone I had never heard of."

Noah spoke in a tired but relieved voice. Because, by now, he knew Andy Andrews. He had just spent 3 hours 21 minutes on the court subduing Andrews, 6-3, 6-4, 6-7, 4-6, 6-2.

Andrews, a blond 1981 graduate of North Carolina State, who came so close to eliminated a seeded player in the U.S. Open, lost this past spring in the semifinals of the Atlantic Coast Conference tournament.

He grew up in Raleigh, N.C., and has an outstanding serve and volleys quite well. He made life quite difficult for Noah, by far the highest-ranked player he has faced in the two months since he turned pro.

"Drawing him first didn't bother me because I was just glad to be in the main draw," said Andrews, ranked 436th currently on the ATP computer. "Once you get in here, everybody's tough. But I felt if I could serve well I could make it tough for him.

"When I first went out there I was real nervous and I had trouble hitting the ball. By the middle of the second set I felt pretty good and I started playing together."

Andrews, who has played only the Penn Satellite Circuit as a pro thus far, was helped by an enthusiastic crowd which packed the grandstand and rooted for the 21-year-old underdog against the 21-year-old "veteran."

"The crowd really helped me out, made me feel good," Andrews said. "I just kept telling myself to hang on."

The match was close because Andrews played up to Noah's level, not vice versa.

In the fifth set, Noah was at his cat-like best even though he had to fight off negative thoughts throughout. "I have not had much confidence lately," Noah said. "When the fourth set ended I felt I would lose."

But he didn't because he came up with four superb shots to break Andrews in the fourth set and because Andrews finally missed some first serves. Noah ended the match with a superb top spin lob which Andrews could only watch as it dropped delicately six inches inside the baseline.

"He won the points when he had to, he played his best then," Andrews said. "I just kept telling myself to keep hitting it and hope something good would happen."

It almost did.