Jose-Luis Clerc, determined to give a "lift of spirit" to his troubled country, all but swept John McEnroe and the United States out of the 1983 Davis Cup competition today.

Holding off a comeback by McEnroe in the fifth set of a key singles match, Clerc used his best clay court play this morning to give Argentina its second point in the five-match set. Then, Guillermo Vilas in doubles led a charge against McEnroe and Peter Fleming that threatened to eliminate the defending Davis Cup champions.

McEnroe and Fleming finally waited out the Argentine team and a clamorous, taunting crowd to win in five sets, 2-6, 10-8, 6-1, 3-6, 6-1, and keep the United States in the match, trailing, 2-1, going into Sunday's final round of two singles matches.

Still, Argentina is poised to win its third consecutive Davis Cup round against the United States on Buenos Aires' clay courts. With McEnroe paired against Vilas, and Clerc scheduled to play Gene Mayer, Argentina must win only one of the matches to take the round.

The key to that advantage has been clay courts, clamorous capacity crowds of 9,000 at the Buenos Aires Lawn Tennis Club and Clerc. "My country is not going through its best moment," he explained emotionally after his victory over McEnroe. "This win is something that can give spirit to the country."

Argentina's spirits have in fact been the overriding characteristic of a playoff in which U.S. players have frequently lapsed on an unfamiliar surface, and taunts and arguments have been as frequent as fine rallies. Singing, whistling fans--including a rowdy cheering section granted free tickets and seated in a separate grandstand--repeatedly interrupted play today and drew two warnings from tournament authorities.

That was one more rebuke than was given to an obviously disgusted and distracted McEnroe, who was defeated for the third time in Davis Cup play in Buenos Aires--out of only four that he has suffered in six seasons of play. McEnroe, though restrained in his questioning of line calls, stalked to the sideline and sat down during one noisy moment, then exchanged words with a nearby fan who, when McEnroe approached, grabbed him by the arm.

"I think the crowd is pretty much the way you would want a crowd to be, very behind their own country," McEnroe said diplomatically to Argentine reporters, adding only that "once in awhile they get out of hand and do things wrong."

Clerc's inspired play in singles for a win of 6-4, 6-0, 3-6, 4-6, 7-5 barely stopped a come-from-behind challenge from McEnroe, whose match followed precisely the scenario hoped for by the Americans when play in the match was suspended Friday night.

Taking advantage of an agreement between the two teams to stop a match any time after 7 p.m. because of growing darkness, U.S. captain Arthur Ashe picked a moment that left McEnroe due to serve today at 2-5, trailing by one service break in the fifth set.

With nothing to lose, McEnroe began with a psychological advantage over the nervous Clerc, and swept his service game in four straight points. Then he quickly broke Clerc's serve in five points, in effect evening the match at 4-5 with McEnroe to serve.

"Last night I couldn't sleep thinking how I would play the first points on my first serve," Clerc said. "I was very, but very nervous, because I knew it was a very important point for my country. And when I lose both points I became even more nervous."

Nevertheless, the initiative shifted to Clerc in the last three games. McEnroe--though far from the stumbling play of his first sets in the tournament--appeared tentative, waiting for Clerc to err, and was sometimes rattled by the noisy Argentine crowd.

McEnroe saved three match points to even the match at 5-5, but Clerc came back to go ahead on McEnroe's final serve. "I think all of a sudden I got a little bit uptight and he (Clerc) got the good shots he needed," McEnroe said.

At Clerc's fourth match point McEnroe was caught off balance by a short return and looped an approach shot long. Clerc bent his knee and shook his fist in joy at the roaring crowd, then ran across the court and leaped into the arms of his sometime-adversary, Argentine coach Ricardo Cano.

"This was one of my best matches," Clerc later said. "I wanted to demonstrate that I go on being Argentine. I'm very happy because I feel that I am finally part of a team."

In the doubles play, the Argentines started strongly, breaking McEnroe's serve three times in the first four sets. Clearly thrown off their usually powerful doubles game, McEnroe and Fleming missed several good opportunities before finally taking the second set by breaking Vilas' serve for the fourth time.

The momentum with them at last, the Americans cracked Clerc's serve for the first time two games later and swept the third set easily. Despite another Clerc-led comeback in the fourth set, the match was never again in doubt.

McEnroe, who took three weeks off before playing here because of an injured shoulder, conceded today that he was still not playing at 100 percent and that the Americans "have been up and down." If the result was a loss in Argentina in the first round Sunday he said, "I feel it would be unfair because the two best teams have to play each other now."