The spectators at Rock Creek Tennis Stadium flocked to the side court to watch Patrick McEnroe in his qualifying match yesterday, perhaps looking for some resemblance to his older brother.

They saw a cool demeanor, one that remained the same after good shots and bad shots.

They saw a 20-year-old with a stubble-covered chin, a sharp two-handed backhand and an improved serve and forehand.

Basically, they saw a fine performance by McEnroe, who defeated Bobby Banck of Buffalo, 7-5, 6-3, in his final qualifying match to earn a spot in the Sovran Bank/D.C. National Tennis Classic which begins today at noon.

"It's not anything I'm not used to," McEnroe said of the attention. "If I saw the name 'Borg' on a draw card, and it was one of his brothers, I'd go and watch, too. It's only natural that people are curious.

"I know I can play with the guys here," McEnroe said of his chances in the tournament, which includes top-seeded Andres Gomez, Thierry Tulasne (No. 2), Martin Jaite (No. 3) and Guillermo Vilas (No. 4), although defending champion Yannick Noah withdrew because of an ankle injury. The semifinals will be Saturday and the finals Sunday.

For McEnroe, there are times, however, when he would rather not be the object of scrutiny.

"Sometimes I'm a little selfish because when you're losing, you don't want the attention," he said. "If you're a college player and you lose, people don't care. But if you're John McEnroe's brother, everybody wants to know."

A smile appeared on his face. "At school Stanford it's nice. Friends come out to watch because they want to see me."

McEnroe, who was the No. 3 singles player as a sophomore with NCAA champion Stanford this spring and is a member of the U.S. Junior Davis Cup team, describes himself as having gone through "peaks and valleys" in his career. He said he had a good year as an 18-year-old, but "messed up parts of my game and lost confidence" the following year.

He has worked on his serve ("When I first went college, I changed my stroke completely") and forehand. And he's finding it's to his advantage to keep his composure on the court.

"I'm pretty calm out there," said McEnroe, who has remained as an amateur by refusing his winnings while playing in professional tournaments for two years, including a doubles championship with his brother John in Richmond in 1984. "Especially in the heat, it doesn't do any good to get hot.

"I think I learned from John. Just because he argued some calls, they viewed him as a brat. I've talked to my dad about that, and we both feel it's not worth the extra hassle."

McEnroe has played in three tournaments this summer, and had one of his best efforts in the Provisional Challenger Series in Schenectady, N.Y., where he gave top-seeded Ramesh Krishnan a slight scare in the first round, losing, 6-3, 6-4.

In 1985, McEnroe did not win a match on the circuit. He said he's had trouble because he puts too much pressure on himself.

"It's a hump I've been trying to get over," he said.

Although he has improved certain aspects of his game, McEnroe isn't satisfied. "I need to work on my serve," he said. "It's nice to get some free points. Basically I need to work on everything."

His Davis Cup coach, John Hubbell, said he is trying to get McEnroe to be more aggressive on his second serve, and to develop his forehand to complement his backhand.

"You watch him," Hubbell said, "and it's obvious he's got a world-class backhand."

The backhand, however, will have to wait a few years before it's put to that test.

"I'd like to see myself as finishing school, then trying to move up," McEnroe said. "I think people are putting a lot of pressure on people to do well at a young age."