INDIANAPOLIS, AUG. 23 -- The Brazilian basketball players went to their U.S. opponents before today's gold medal game and did everything except beg for mercy. They praised the U.S. men's team for being the best in the world, fell behind by 20 points in the first half, then came back to record probably the biggest basketball upset in the history of the Pan American Games.

Behind the accurate and almost carefree three-point shooting of Oscar Schmidt, Brazil beat the United States, 120-115, before 16,408 in Market Square Arena.

The Americans sat on the bench stunned, their faces looking like they'd seen the end of the world. And at the other end of the court, Brazilian players wept and dived on top of each other, holding on for dear life and every so often wiping their eyes to look up at the scoreboard and make sure it really happened.

It was only the second loss in Pan Am history for the United States, which had won 34 straight in the competition, dating back to 1971.

No wonder Schmidt said, "This is the biggest victory of our lives. All of us. We hear that 20 million people are back at home watching this live on television . . . The U.S. is the best team. We know that. We expected them to be No. 1 for always. But we were just better for today. Just for once. I can't believe we beat them. None of us can believe."

The United States lost today not only because Schmidt scored 35 of his electrifying 46 points in the second half, but because U.S. center David Robinson played only 15 of a possible 40 minutes on account of foul trouble.

"Without David in there," U.S. Coach Denny Crum said, "we just were not as good as we wanted to be."

Before Robinson got into foul trouble, the 7-footer was as dominant as he ever was in a Naval Academy uniform. In just 15 minutes, he scored 20 points, grabbed 10 rebounds and blocked five shots.

When he picked up his fourth personal foul with 17 minutes remaining, for hanging on the rim after a dunk to protect himself from being undercut -- a technical foul counts as a personal foul in international rules -- it didn't seem like any big deal. The United States was ahead, 77-62, and seemed to be cruising toward the gold medal it was expected to win.

But the U.S. team, made up of 11 underclassmen and Robinson, is young and inexperienced, especially when compared to Brazil, whose players' age averages about 28.

With Robinson on the bench, Brazil scored nine straight points, six on three-pointers by Schmidt, to close to 77-73. Now, the game could begin.

The Brazil players already were given a boost as the first half ended when a 40-foot three-point basket at the buzzer by Marcel Souza (31 points) cut the lead to 68-54.

"We were down to the U.S. by 26 points at halftime last year in the world championships, but we got it down to five with only eight minutes left," Schmidt said. "We were all thinking that again. We figured we'd put more pressure on them and see what happened."

The form of pressure Schmidt and Souza chose was the three-point shot. In the United States, jump shooting is a lost art; in South America, it is the way to play.

"We have a saying in Brazil," said Souza, a physician in his spare time. "We are the piano players and our teammates are the piano carriers."

The carriers passed and rebounded, Souza and Schmidt -- who averages 33 points per game in a professional league in Italy -- shot.

This is the sequence that changed the game while Robinson sat on the bench with four fouls: Schmidt's three-pointer gets Brazil within 81-80. Schmidt's three-pointer puts Brazil ahead, 83-81. Pervis Ellison of Louisville makes two free throws for 83-83. Schmidt hits another three-pointer for 86-83. Rex Champan of Kentucky hits a jumper. Schmidt for three, 89-85.

Just about every U.S. player tried to check "The Fabulous Oscar," as Schmidt is called in Brazil. None succeeded.

Souza told the Americans they were faster and quicker, but the Americans couldn't shoot straight. The United States would make just two of 11 three-pointers for the game (and was outscored by 30-6 on three-point shots), so hitting two-pointers wasn't enough. And it shot only 16 of 46 in the second half.

"If we play the traditional way," Brazil Coach Ary Vidal said, "we cannot beat the U.S. If we play the way we do, however, we have a chance."

By the time Robinson came back in the game, with 7:41 left, the United States was down, 95-94. Schmidt had scored 23 points in the 10 minutes Robinson was out.

It went that way much of the rest of the game. Robinson fouled out with 6:05 to play. When Schmidt hit consecutive two-pointers in the final two minutes to put the Brazilians ahead, 112-104, it was apparent the U.S. run was over.

And there were questions to ask: What did Robinson think of picking up the fourth foul for hanging on the rim? "I didn't feel like I hung on the rim," he said, "but the ref did."

Could Brazil have won if Robinson had played, say, 30 minutes? "If he had played 25 minutes, I don't know," Schmidt said.

And how could the United States lose a 20-point lead (62-42 with three minutes left in the first half)? "We missed a whole lot of unmolested shots," Crum said. "Totally unmolested. But we played hard and we played together. Brazil just knew what they wanted to do . . . and they did it."