Guillermo Vilas and Jose-Luis Clerc are not merely tennis players in their Argentine homeland; they are national heroes.

They are heroes of a sort in Washington, as well. Together, they have dominated the last 10 Washington Grand Prix tournaments. Five times since 1974, either Vilas or Clerc has won. Seven times, at least one has been in the final.

In 1981, they played each other for the title, and Argentine flags waved as the crowd cheered on every point as Clerc won, 7-5, 6-2.

Today, by virtue of Clerc's 7-6 (7-4), 6-2 victory over Slobodan Zivojinovic yesterday, Vilas and Clerc will meet in a third-round match of the D.C. National Bank Tennis Classic at Rock Creek Tennis Stadium.

Two other Argentines, Martin Jaite and Marcelo Ingaramo, also advanced to the third round by winning yesterday. Jaite beat 17-year-old amateur Jaime Yzaga, 6-3, 6-4, and Ingaramo defeated Diego Perez, 7-5, 6-3.

Joining the Argentine quartet were top-seeded Jimmy Connors, fourth-seeded Miloslav Mecir, eighth-seeded Libor Pimek and 15th-seeded Mark Dickson. In night matches, Connors swept into the quarterfinals by defeating 16th-seeded Lawson Duncan, 6-1, 6-1, and Mecir became the last player in the draw to play a match as he outlasted Juan Avendano, 2-6, 6-2, 6-1. Pimek pounded out a 6-1, 6-4 victory over Fernando Luna, and Dickson beat Christo Steyn, 6-4, 6-2.

Duncan, 20, has strong ground strokes and a big forehand, so it seemed his topspin game might give Connors trouble on clay. But Connors nullified the effect of the surface.

"I thought it would be more of a clay-court game -- ground strokes and stuff," said Duncan, who last year won a record 64 matches for Clemson and made it to the NCAA final as a freshman. "But he hit the ball deep and really low. I just felt like I had no rhythm."

Connors broke Duncan in the second game. Duncan had a break point in the next game, and it looked as if he had Connors beaten when he came to the net for a smash, but he mis-hit it, and Connors came back to win the game.

Duncan got to deuce in the fifth game after Connors netted a forehand, but Connors held again. He broke Duncan to go up, 5-1, and won the set on his serve.

Connors broke serve in the third and seventh games of the second set.

"You just go out and do what it takes to win the match," Connors said. "For me there's no plan, no strategy, nothing.

"I played a little better tonight than last night. As long as I keep taking it up a notch every round I'm in good shape. It's been good enough for 14 years."

Mecir looked as if he was going to be upset last night, losing the first set to Avendano, a qualifier ranked 187th in the world. But Mecir, who plays long, lethargic points, almost routinely goes three sets. He lulls his opponent to sleep, taking the pace off the ball and slowly moving it around the court, then using surprising speed to come to the net.

"I was worried in the first set because I was missing points," he said, adding that playing under the lights for the first time in a while bothered him. "I was almost kind of sleepy."

Clerc had far from an easy time with Zivojinovic, the 6-foot-4 1/2 Yugoslav who upset Mats Wilander in the first round at Wimbledon.

Serving in the first game, Clerc was taken to deuce by Zivojinovic, but as he seemed to do in almost every tough spot of the match, Clerc won the game with his serve, pulling out an ace and a service winner to hold.

"I think I lost because he was serving so good," Zivojinovic said. "I had a lot of chances in the first set to break his serve, but it was really hard to return. When I was returning, he was coming with his unbelievable forehand."

"My second serve was one of the best things I did today," said Clerc.

Neither came close to breaking again until the 11th game, when Clerc was called for a foot-fault on his first serve, then put his second into the net to trail, 30-40. But Clerc pulled back to deuce and won the game.

Zivojinovic went up, 40-30, in the 12th game, and forced the tie breaker with a hard forehand that just caught the base line corner.

In the tie breaker, Clerc went up, 4-2, on a forehand winner that left Zivojinovic shaking his head from 12 feet away. He took a 6-3 lead when Zivojinovic netted a forehand, and won the set when he caught the sideline with a return.

The first break of the match came at 2-2 in the second set. After netting a forehand, Zivojinovic hit a passing shot long to lose the game.

"After I broke him the first time I felt more confidence," Clerc said.

"It was really hard for me to know if he was going to serve to my backhand or my forehand," said Zivojinovic. "He really surprised me."

Clerc broke serve in the eighth game to go up, 5-3, with another backhand that caught the sideline. Clerc served a love game for the match.

Vilas has credited the Argentine success here not only to the clay courts, but also to the weather, which is closer to Argentina's than Europe's.

Vilas was already a national hero in 1974 when he played a Davis Cup match at the Buenos Aires Lawn and Tennis Club. Kneeling by the net that day, scampering after netted balls, was a 10-year-old named Martin Jaite.

Three years later, the next great Argentine tennis player, Clerc, was playing Davis Cup. Once again, Jaite skidded across the clay as he retrieved the mis-hit balls of his nation's heroes.

"Vilas was the first national hero, and he always will be," said Andy Garcia, who coaches both Clerc and Jaite. "Then, there was Clerc."

Now, he said, gesturing to Jaite, 20, "We have another one coming."

Last week, Jaite made it to the final of the U.S. Pro Tennis Championships in Brookline, Mass., before losing to Wilander.

Yesterday, Jaite used a break in the second game to go up, 4-1, against Yzaga. Yzaga broke back in the seventh game, which went to deuce seven times. Jaite broke right back in the eighth game, which went to six deuces before Yzaga's two unforced errors made it 5-3, Jaite.

Jaite said he hasn't changed his game any, but attributes his success to confidence.