Guillermo Vilas, comfortable with the Washington area and uncomfortable with reports of retirement, defeated Thierry Tulasne in two sets last night in the first round of the D.C. National Bank Tennis Classic at the Rock Creek center before a record crowd of 9,200.

Vilas eliminated Tulasne, 6-1, 6-3, demonstrating he still possesses considerable clay court ability, although he was unseeded for the first time in seven appearances in this tournament. He has won it three times.

"Some places you just feel at home," he said. "Whenever I arrive at this airport, I can say I've won this tournament before. It makes a difference."

In another featured match, Dan Goldie of McLean was on the court all of 15 minutes, Jimmy Brown finishing off the world's top-ranked amateur, 6-3, 6-4, in a continuation of a rain-delayed match. But Jaime Yzaga, a 17-year-old from Peru, took up the role of ingenue for Goldie, upsetting Michael Westphal, 5-7, 7-5, 6-1.

Stefan Eriksson defeated Hans Gildemeister, 6-2, 6-1, to set up a meeting with No. 1 seed Jimmy Connors today. NCAA champion Mikael Pernfors ousted Joan Aguilera, 7-6 (9-7), 6-3, and will meet third-seeded Yannick Noah tonight.

Another young area player, Rodney Harmon of Richmond, suffered the same fate as Goldie, losing to Christo Steyn, 6-3, 6-0. Harold Solomon, a Washington-area native now living in Florida, defeated Jaro Navratil, 6-2, 6-0. Also, 15th-seeded Mark Dickson defeated Mel Purcell, 6-1, 6-3, and 16th-seeded Lawson Duncan beat Roberto Arguello, 6-1, 6-2.

Play yesterday was marked by uncomfortable humidity, a crowd surpassing the record of 9,171 set in 1983, and noise. Busloads of children, blasts of radio music and a popcorn popper situated directly next to the stadium court had chair umpires pleading for quiet. Tickets from Monday's rained-out session were still good and many of the spectators were returnees, which accounted for the record crowd.

But part of the attraction was Vilas, who has become a crowd-pleaser here. He broke Tulasne in the second game of their first set, taking a 3-0 lead, and again in the sixth game to go up by five.

In the second set, he broke service in the first game, which went to six deuces, then once more for the match.

Vilas hasn't won a tournament in two years and has dropped to No. 37 in the rankings. But he has a new training program and coach. His 10-year coach Ion Tiriac, currently manager of 17-year-old Wimbledon winner Boris Becker, was replaced by old friend Ernesto Ruiz Bry four months ago.

The change, because of increasingly conflicting schedules with Tiriac, seems to have done Vilas good. He gained the semifinals at the U.S. Pro championships last week, losing to eventual winner Mats Wilander.

"It's been my best week of the year," he said. "I'm doing much better than before. I think of it in those terms."

Reports he was retiring began several weeks ago at a tournament in Italy. Vilas refuted them quickly, and reiterated his intentions last night.

"Definitely not," he said. "You always have times when you think: should I be doing this or going skiing? But I love tennis."

Goldie was not at his best after a rainy week at Wimbledon in which he received a slight leg injury. He lost there in the the first round to 30th-ranked Paul Annacone in a five-setter.

Goldie, a Stanford senior, is ranked 108th in the world. He was last year's surprise, reaching the quarterfinals with victories over Brian Gottfried and top-seeded Jimmy Arias.

But yesterday he never got started. He was behind, 6-3, 4-4, when the Monday match was stopped by rain. When play resumed yesterday, Brown broke him in the first game and held serve easily for the match. Goldie won only two points on his serve and only one point as Brown served out the match.

Yzaga may become the dark horse that Goldie was last year. The 17-year-old wild-card entry was the French Open junior champion and a semifinalist in the junior Wimbledon tournament this year. He is ranked No. 274 in the world.

He broke Westphal, ranked 70th, in the 11th game of the second set with a hard backhand down the line. The teen-ager held serve easily to even the match.

Yzaga dominated the third set. Westphal held serve in the first game, but that was it. Yzaga broke him in the third game, then held serve with an ace for a 4-1 advantage. He broke again in the fifth and seventh games for the match.

Yzaga is a pupil of Colon Nunez, who coaches Andres Gomez, the defending champion here. A diminutive player who likes to make opponents run, Yzaga wore down Westphal with his tactics and fine touch.

The top-seeded players will make their first appearances today. Connors will face Eriksson in the third match of the afternoon, preceded by seventh-seeded Arias against Guy Forget, who won a long match last night against Eduardo Bengoecheca, 6-7 (4-7), 6-2, 7-5.

In evening matches beginning at 7 o'clock, Noah will meet Pernfors and No. 5 Aaron Krickstein will play Brown.