]CBS SportsLine.com wire reports NEW YORK -- Lastings Milledge was high-fiving fans along the right-field railing, the same way Cal Ripken did 11 years ago on his "victory lap" in Baltimore after breaking Lou Gehrig's record for consecutive games played. Ahh, the exuberance of youth. Turns out, the celebration was premature -- and it irked a few folks in both dugouts. Pedro Feliz hit an RBI single in the 12th inning and the San Francisco Giants finally held off the Mets 7-6 Sunday, overcoming a breakout performance by New York's prized prospect. With the Mets down to their final strike in the 10th, Milledge hit his first career homer off All-Star closer Armando Benitez to tie it at 6-all. The 21-year-old rookie raised his index finger toward the sky as he rounded first and came out for a curtain call. Then, as he jogged out to right field for the 11th, he slapped hands with dozens of fans leaning over the railing. "We weren't too happy about that. But he's a young kid," Giants reliever Steve Kline said. "I don't know if he's going to be slapping five with everybody after he goes 0-for-15 and the New York fans are booing him. But in the heat of the moment, you can't blame the kid. He knows better. I think he genuinely knows he did wrong." The Mets also took notice. "Oh, boy. He has a little growing up to do," outfielder Cliff Floyd said. "I'll just mention to him the consequences that come along with that. If that's what you want to do, you do that. But at the same time, if you want guys throwing at your head constantly, you proceed to do it that way. "He has the talent and everything, but you have to understand the game at this level. At Triple-A they're going to treat you like a king, and what's wrong with that? When you come here, without losing your mojo, you've got to bring the mentality down. If you can do that, you'll earn the respect of a lot of people." Milledge heard it from his manager, too. "I had a little conversation with him about that. I told him to tone it down a little bit," Willie Randolph said. "He got excited about his first big home run. Wouldn't you? I talked to him about it -- it won't happen again." Milledge also hit a go-ahead double and made a sliding catch in right field in his fifth major league game, quickly winning over New York fans who have been reading about the gifted youngster for a while now. "Now I know what's expected. It was a rookie mistake. We learn from it," Milledge said. "I was just excited to get the team back. If it was just a solo homer that meant nothing for the team, I wouldn't have been that excited." Milledge's two-out double on an 0-2 hanger from starter Matt Morris put the Mets up 3-1 in the sixth. The two RBI were the first in the majors for Milledge, called up from the minors Tuesday after right fielder Xavier Nady had an appendectomy. "It was pretty disappointing because we should have won the game. We let it slip away all day," Milledge said. "It wasn't as though we beat ourselves, they just beat us."