INDIANAPOLIS, AUG. 15 -- The Cubans hadn't lost a Pan American Games baseball game in so long they had developed a team swagger. Through a 33-game streak that spanned 20 years they had become the Yankees of amateur baseball, a team the United States players watched in mesmerized awe.

But today, a young, inspired baseball team gave U.S. amateur sports one of its brightest moments when Georgia Tech's Ty Griffin smoked a two-run homer with two out in the ninth to lift the host nation to a stunningly dramatic 6-4 victory over Cuba before a delirious crowd of 13,500 at Bush Stadium.

The American players had a sort of restrained joy, happy to have broken Cuba's 20-year stranglehold on the Pan American Games, but fully aware that they almost certainly will have to meet Cuba again, perhaps next weekend for the gold medal.

But to say this game meant nothing would be a crass misstatement. "Do we get any kind of medal for this?" U.S. Coach Ron Fraser said, jokingly. "Oh, we gotta play again."

Police security was said to be particularly heavy at Bush Stadium in light of Friday night's melee involving several Cuban boxers going into the stands at their venue to battle with anti-Castro specators. But there were no incidents other than police ordering fans in the bleachers to take down a huge American flag that was blocking the view of others, including a group of Team Cuba supporters.

If the U.S. team derived some sort of psychological advantage from beating Cuba two out of five exhibition games last month in Havana, then today's victory must have sent the Americans' confidence and hopes soaring as high as Griffin's game-winning shot, his second homer of the game. The United States is 5-0, Cuba 4-1 in the Games round robin.

Cris Carpenter, a University of Georgia star bound for the St. Louis Cardinals, pitched the final four innings in relief, allowing only one hit, to pick up the victory. But he couldn't have done it if his teammates hadn't scored four runs in the final three innings.

Going into the seventh the Cubans led, 4-2, on the strength of a pair of two-run homers -- the second a fifth-inning tie-breaking 405-foot drive to center by Omar Linares.

But the switch-hitting Griffin, with two out and nobody on base in the seventh, tagged Rogelio Garcia for a left-handed homer that cut the lead to 4-3.

The Americans stole a run in the eighth. After University of Tampa star Tino Martinez doubled to start the inning, Mike Fiore helped atone for two potentially disastrous base running errors by laying down a bunt that moved Martinez to third.

The United States caught a break when Garcia, covering first base on the play, got tangled up with Fiore. While the two fell, Martinez took a peek at the pileup, then bolted around third to score the tying run, easily.

Meantime, Fiore had been called out and Jerry Weinstein, the U.S. first base coach, was arguing that decision while Martinez was making his dash home. But Cuban Coach Higinio Velez protested only mildly, and the run stood.

Carpenter mixed a nasty slider with his 91-mph fastball to keep the Cubans off balance in the eighth and ninth. And the partisan U.S. crowd gave the American players a long, loud standing ovation as they prepared for the ninth.

But there was no immediate indication it would be the final inning. Pablo Abreu, a big, menacing left-hander, came in to throw the ninth. And the first two U.S. hitters, Pepperdine's Rick Hirtensteiner and Texas A&M's Scott Livingstone, had no clue against Abreu and struck out swinging.

A couple of major league scouts said earlier in the week that Abreu, who has a 90-mph fastball, gets too cute and tries to throw too many curves. How prophetic.

On a no-ball, two-strike pitch to the No. 9 U.S. hitter, Larry Lamphere (sacrifice bunt, and two strikeouts), he needlessly threw a curveball and it hit Lamphere. That saved a plate appearance for Griffin, the budding star second baseman vainly drafted by the Baltimore Orioles in the 12th round two years ago.

Griffin had already been a pivotal figure. Besides his homer in the seventh, he singled to start the first and trigger a rally that gave the United States a 2-0 lead (that might have been much larger had the University of Miami's Fiore not carelessly gotten himself doubled off second base).

But his day wasn't all roses. In the fourth he made an error on a routine ground ball, which was magnified when the next batter -- Orestes Kindelan -- hit a homer that tied the game, 2-2. "I wanted to just leave the field right then and go home," Griffin said.

Griffin and Fraser had had an interesting little discussion before the game. Griffin, a singles hitter his entire life before this week, had his chest stuck out over his show of power the last week (one home run, two deep doubles) and asked Fraser to move him from leadoff to No. 3.

"I told him, 'Your job is to bunt, get on base and steal,' " Fraser said he told Griffin. Fraser, in fact, was so sure Griffin wasn't going to hit another home run he nearly had Lamphere try to steal.

But with a one-ball, one-strike count, Griffin saw Abreu hang a curve ball. It landed on the other side of the left field wall, 350 feet away.

"I only started switch-hitting two years ago," said Griffin, who grew up in Tampa, Fla., and made a dramatic international debut in the 1980 Little League World Series when he hit a home run against champion Taiwan. "This is the first time I've hit home runs from both sides of the plate and probably the last. I'm very surprised."

When it was over, the Americans hugged and kissed one another, and the Cubans, in a lovely gesture of sportsmanship, immediately ran out of their dugout and crossed the field to congratulate the U.S. team.

The Cuban players did not seem stunned they had lost, largely because they -- like some of the scouts -- believe the U.S. team is chock full of talent and hardly the underdog people perceive it to be.

"A team has to lose and it was just our time to lose," Cuban left fielder Lourdez Gurriel said philosophically. "We can't feel like the sky fell on top of us. We just have to be better and be ready for the real important game."

Velez said, "They have a complete team: pitching, speed, power, everything. I've been saying for the last three days that they have a complete team."

The United States has two games remaining before the medal round begins Friday. But Ty Griffin, who on this day assumed the role of another Georgia Peach, Ty Cobb, thought about what the Cubans must have felt, not having lost a Pan Am baseball game since 1967 in Winnipeg.

"You know," he said, "that they'll be out for revenge."