NEW YORK -- During the fourth inning of the RBI Northeast Regional junior division title game Monday, Yankee Stadium public address announcer Paul Olden asked that all fans in attendance return foul balls hit their way.

Such a request would draw an outrage from the fans who pack this place for every Yankees home game, but the circumstances were different Monday.

For one, Olden was making the announcement from a makeshift desk in foul territory on the first-base side of the field. And the fans he was speaking to had a higher stake in this game than they would in Yankees games.

Kids between 13 and 18 years old dominated the field normally reserved for Major Leaguers, with the clicking of metal bats providing the dominant sound for hundreds of family members and friends cheering them on throughout the afternoon.

Jersey City beat the Greater New York Sandlot Athletic Alliance, 4-3, in the junior division (ages 13-15) regional title game before GNYSLAA won the senior division (ages 16-18) game over Jersey City with a 2-1 victory in walk-off fashion.

Each winner will represent the region at nationals Aug. 9-14 in Minnesota.

RBI, which stands for Reviving Baseball in Inner Cities, is a youth program intended to promote participation and interest in baseball and softball while encouraging academics.

Major League Baseball runs the program, and eight different regions host the RBI World Series each summer.

Harlem RBI hosted the Northeast Regional, culminating Monday with Joe Arena's walk-off two-run single to lift GNYSLAA to the the senior division regional title.

"It's a great feeling," said Arena, who hit the decisive grounder to left field with two on and nobody out in the bottom of the seventh. "To get a walk-off hit as a kid at Yankee Stadium, I'll probably never beat this."

Arena was chased and eventually mobbed by teammates near second base after delivering the victory, prompting the playing of Frank Sinatra's "New York, New York" from the loudspeakers.

"I kept thinking, 'Oh God, they're going to kill me,' " Arena said of the sight of his teammates.

Arena, a Westchester native who will play baseball at C.W. Post, is actually a Mets fan who was making his first trip to Yankee Stadium in any fashion.

He joined every one of his teammates in playing his first game on the big league diamond.

Arenas' coach, Shaun Manning, played in a high school All-Star Game at the old Yankee Stadium. He said he told his players in the dugout in the middle of the seventh to stay on top of the ball and remain aggressive, thinking it was only a matter of time before their bats broke through.

"It couldn't be any better," Manning said of the ending. "The kids will remember this forever."

Jiovanny Aguiar, in his first season coaching the junior division Jersey City squad, had six returning players from last year's club, which lost to Boston in the regional title game.

Despite the Yankee Stadium experience for some of the team, Aguiar admitted it was tough trying to balance the awe of playing on a big league field while knowing they had plenty at stake once they took the diamond.

"When they first pulled up, you could see their eyes open," Aguiar said. "They're like, 'This is where Derek Jeter plays.' And you have to remind them not to settle."

Aguiar's Jersey City team celebrated its victory in grand style, forming a dogpile near the Yankee Stadium mound after the final out was recorded on a fly ball to center field.

Each team shook hands before home-plate plaques were given out to each Jersey City junior, with the GNYSLAA seniors going through the same routine nearly three hours later.

For Aguiar, the message beforehand was simple.

"Take care of business, and let's celebrate after," Aguiar said.