NEW YORK -- The rookie pitcher who got the biggest outs for the Mets on Saturday was not the one with all the hype.
Marlon Byrd, David Wright and Daniel Murphy each had an RBI single for the Mets, who handed Cole Hamels his latest defeat and snapped Philadelphia's seven-game winning streak at Citi Field. Another rookie, Juan Lagares, had a run-scoring single among his three hits.
Germen (1-1) escaped a bases-loaded jam and struck out three in 1 2/3 hitless innings for his first major league win.
"He did an amazing job," Byrd said. "That could be a scary lineup to face when you're a young kid."
Jimmy Rollins hit a leadoff homer, and Chase Utley had a two-run shot in the ninth for the Phillies. They put the potential tying run on second before Bobby Parnell retired Darin Ruf on a game-ending liner to second.
Wheeler wiggled out of early trouble in his sixth major league start, but the prized right-hander needed 106 pitches to get through 4 2/3 innings in 93-degree heat.
"I just told him to hang in there. I just said, `Look, you can only do it as best you can for as long as you can," Mets manager Terry Collins said. "You could just tell he was out of gas. Yeah, I could have let him go one more hitter, but we're trying to win games, too."
Hamels (4-12) allowed three runs in a 35-pitch first inning and was pulled for a pinch-hitter after five. The three-time All-Star and 2008 World Series MVP leads the NL in losses.
Hamels has always had trouble with the Mets. The left-hander, who was 2-0 with a 1.57 ERA in three previous July starts, dropped to 6-12 in 24 outings against them.
Coming off a gem in San Francisco but pitching for the first time in 10 days, Wheeler gave up a two-strike single to Hamels to start the fifth. The Phillies loaded the bases with nobody out, but all they managed was Utley's sacrifice fly.
All-Star slugger Domonic Brown flied out on a 3-0 pitch. Wheeler walked Ruf to load the bases again -- and was lifted one out short of qualifying for a win.
Wheeler kept his back to Collins as the manager marched to the mound, then handed over the ball and disappeared down the dugout runway. Collins followed moments later, and Wheeler was back on the bench to greet Germen with a high-five after he struck out streaking Delmon Young to preserve a 3-2 lead.
"Right now, the kid's doing his job," Young said. "He's been pitching in big situations."
Collins said he didn't want Wheeler to be trailing when he came out. In his only other outing at home, the 23-year-old was beaten by Washington 13-2.
"That was definitely tough. I wanted to get through that inning," Wheeler said. "Not just for the win, but just to get out of that jam so we didn't have to use the bullpen earlier than we had to.
"My pitch count was high, and I guess Terry thought that was the right time to take me out. It worked out for us."
Wright hit a run-scoring single in the fifth, and Murphy added his RBI single in the seventh. LaTroy Hawkins worked the eighth, and Parnell got three outs for his 18th save despite allowing Utley's second homer in two days.
It was the first home run given up by Parnell since Aug. 4, 2012, at San Diego.
Still struggling to command his lively pitches and get ahead, Wheeler has however shown the ability to bear down in a jam. He held Philadelphia hitless in five at-bats with runners in scoring position, leaving opponents 4 for 32 (.125) in those situations during his brief big league career.
"I really concentrate. I really pride myself, if guys are in scoring position, that they're not going to score," Wheeler said.
Rollins drove Wheeler's third pitch to right for his 45th career leadoff homer, breaking a tie with Brady Anderson for fourth place in major league history.
It was Rollins' first home run in 162 at-bats since May 31. He has a 16-game hitting streak against the Mets.
New York came right back in the bottom of the first with the help of two walks by Hamels, who issued one free pass over 23 innings in his previous three starts combined. Byrd lined a run-scoring single, Lagares fisted an RBI single into shallow right, and Anthony Recker knocked in another by beating out a double-play ball after third baseman Michael Young double-clutched.
"You can't always go out with your best stuff, but you have to make the adjustments," said Hamels, who struggled to grip the ball properly with sweat pouring down his hand. "I wasn't able to make the adjustments as quickly as I would have liked in that first inning."
Rollins' other leadoff homer this season came on May 10 in Arizona. ... Delmon Young had three hits for the second straight day. ... With the Mets facing a left-hander, Josh Satin started at 1B instead of Ike Davis. Satin made a two-out error in the ninth that nearly became costly. ... Harvey is 3-0 with a 1.37 ERA in four career starts against Philadelphia. Lee is 5-1 with a 2.09 ERA in nine games against the Mets.
Fantasy baseball: Jared Walsh and the new-look Angels
Eric Karabell takes a look at all of the top fantasy baseball stories from the weekend, including the end of an era in Anaheim, as we say goodbye to Albert Pujols.
Fantasy baseball forecaster for Week 6: May 10-16
Set your lineups for the week ahead in fantasy baseball with our forecaster preview, which features pitcher rankings, two-start pitchers, hitter ratings, schedule observations and more.
Fantasy baseball forecaster: Pitcher projections for the next 10 days
Keep up to date on who is pitching -- and how well they're expected to do -- with our forecaster, which provides a rolling 10-day outlook of every team's probable starting pitchers with game score projections.
Are too many strikeouts bad for MLB?
Tim Kurkjian voices his concern over the higher number of strikeouts this season in Major League Baseball.
How the culture of baseball is changing
Joon Lee, Buster Olney, Tim Kurkjian and Jeff Passan discuss the culture shift in baseball as players understand and use social media and marketing more than in previous generations.
The State of Baseball: Inside the biggest questions MLB is facing with the future of the sport at stake
Are games too long? How can baseball maximize its new generation of stars? We dig into the topics that will shape the game far beyond this season.