The Pan American Games had their first splendid, full-bore, jump-up-and-down, scream-your-head-off superstar track controversy tonight as James Robinson of the United States beat Cuba's Alberto Juantorena by a halfstride in the 800 meters.

Robinson blasted his way past a Jamaican runner with 60 meters to go, then scooted past Juantorena on the inside to win a dramatic tactical battle in 1:46.3, a Pan Am record.

The 24-year-old Robinson then risked gray hair for two hours before a five-judge panel upheld his victory, disallowing a foul claim by Jamaican Owen Hamilton.

This race was full of ambiguity, controversy and murky gray areas.

Without question, Robinson was boxed in behind a three-abreast wall of leaders with just 60 meters to go.

"No time for any more moves," Robinson said.

So Robinson, who also defeated Juantorena once in 1978, barreled straight ahead, hitting the inside runner (Hamilton) in the back of the neck, knocking him off balance and out of contention. Sport now has two "Truck" Robinsons.

Juantorena then may have made an uncharacteristic strategical error, leaving the inside open instead of closing down in front of Robinson. The American from Oakland, Calif., six inches shorter, blazed past the Cuban horse with a telling burst.

Juantorena labored to the finish line, uncharacteristically exhausted.

"I have no feelings about the judge's decision," Juantorena said. "I ran well. I am improving. I am not ready yet."

Robinson pursued Juantorena and grabbed his hand to raise it high after the race.

"I wanted to show everyone that he is still No. 1," Robinson said. "It's nice to beat him, but both times I have won, he's been at a disadvantage. He's coming back from an injury to his lower back and he's not right yet. I had worked hard for this.

"Next month at the World Cup when everybody is at their peak - that will prove something."

Another indeterminate race was run here tonight. Renaldo (Skeets) Nehemiah of Maryland got out of his sickbed to set a Pan Am record of 13.38 in a 100-meter hurdles heat. His time bettered the 13.54 By Cuban arch rival Alejandro Casanas, who ran a few minutes later.

"I think I'll be ready for the final on Wednesday," Nehemiah said. "I'm sweating out more of this sickness every day. I had a temperature of 103 degrees for five straight days and I'm still weak. I've only improved the last two days.

"I don't know when I've felt so nervous before a race - shaking like you do when you have the flu. I expected a poor time, like 13.8 or 13.6 at best. But I guess I'm very relaxed now because, coming back from this sickness, I'm not asking anything special from myself."

If the Nehemiah-Casanas rivalry has become bitter since they had a run-in-here at Escobar Stadium Saturday, it had nothing on the Robinson-Hamilton spat tonight.

"It was flagrant," Hamilton said of the shoving incident. "He elbowed me in the neck and practically knocked me down. I was right in my (insied) lane and he came way over the line to get through."

The judges saw it a quite different way, agreeing with Robinson's version:

"I was in Lane 2 and I saw a hole open between Hamilton, who was in Lane 1, and Juantorena, who was on the outside of Lane 2. As I moved, Hamilton tried to seal me off by moving halfway into my lane. He was over the line into my lane, so it wasn't my fault."

The spectacular race was the highlight of a track and field program that produced a 1-2 sweep by U.S. women in the 800 meters by Essie Kelley, Prairie View, Tex., and Julie Brown, Northride, Calif.

Mike Woodson's 30 points and a smothering defense powered the unbeaten Untied States men's basketball team to a 99-73 thrashing of Argentina.

Elsewhere, Bobby Knight, the controversial U.S. basketball coach, who said "I'm getting crucified by my silence," called a Tuesday press conference to clear the air concerning a Sunday brush with a policeman, and the U.S. Greco-Roman wrestling team won foru gold metals and a total of 10, one in every category.

That helped push the Americans' leading accumlation to 78 gold medals in these hemisphere Olympics, with 180 total medals. Cuba had a 48-98 gold-total count and Canada 19-98. Argentina was far back in fourth at 9-27.

In the women's 800, Kelley, the AAU champion, held off a late surge by Brown to win in 2:01.2.

By far the most impressive haul of the night for the Americans was in Greco-Roman wrestling: four gold, four silver and two bronze.

Barbara Brown scored 16 points and Carol Blazejowski, Ann Meyers and Jan Trombly added 12 each to carry the unbeaten United States women's basketball team to a 92-58 rout of Mexico. CAPTION: Picture, U.S. runner James Robinson spurts past Cuba's Alberto Juantorena in stretch to win Pan Am 800 meters in upset. AP