NEW YORK -- Jonathon Niese stood in the center of the clubhouse, accepting congratulations from a parade of grateful teammates.
His first major league win was a crucial one for the New York Mets.
"He threw an unbelievable game," Jose Reyes said. "We needed that game there."
Reyes and Carlos Beltran also connected to help the NL East leaders avoid a costly sweep after they let the opener slip away for Johan Santana. New York is 2 1/2 games ahead of second-place Philadelphia -- three up in the loss column -- with 15 to play.
It was at this stage last season when the Mets began their epic collapse. They had a seven-game cushion before going 5-12 down the stretch and letting Philadelphia charge past them for the division crown.
Beginning their final 17-game stretch this year, the Mets squandered a late lead in the first game but rebounded in the nightcap. They have won 21 of 29 overall and desperately want to prevent another September slide.
"Because of what happened last year, we just have to deal with it," manager Jerry Manuel said between games. "We have to answer the questions daily, but that's OK."
Jeff Francoeur hit a tying single in the eighth inning of the first game and Atlanta rallied against Santana and the Mets' bullpen, beating New York 3-2 for its first one-run road win in more than a year.
Omar Infante's sacrifice fly put the Braves in front, capping a three-run eighth.
Mike Gonzalez closed out Atlanta's fourth straight win with a perfect ninth and the Braves won a one-run game away from home for the first time since a 7-6 victory on Aug. 9, 2007, also at Shea Stadium.
Atlanta had lost 22 such games in a row this season and 29 overall -- the longest streak of its kind in major league history, according to the Elias Sports Bureau.
"We enjoyed it. There was a lot of excitement in that dugout, in that locker room, when you win a game like that," Kelly Johnson said. "Let's make it hard on these guys. Maybe they collapse again."
Niese (1-0) did his best to prevent that.
The 21-year-old lefty, born the day the Mets won the 1986 World Series, allowed six hits and struck out seven. He was admittedly nervous for his debut Sept. 2 and got roughed up at Milwaukee.
"I was more relaxed, obviously. I just worried about taking a deep breath between pitches and just executing and it all worked out," Niese said.
Beltran also doubled, singled and scored twice. Wright hit a two-run shot off Jo-Jo Reyes (3-11) in the first and Fernando Tatis polished off the inning with a two-out RBI single. Tatis and Reyes each had three hits.
Niese was tabbed for this start after Friday night's rainout forced the doubleheader. The Mets, missing injured John Maine, pushed back Pedro Martinez until Monday night at Washington, saying they didn't want to start two unproven pitchers in that four-game series.
The club's top pitching prospect, Niese delivered in a big way. With the scattered crowd chanting "Let's Go Niese!" he got Omar Infante to foul out for the final out of the eighth and pumped his first.
"He threw a lot of strikes. Got that real slow, good curveball," Braves manager Bobby Cox said. "He didn't look like a 21-year-old kid on the mound to me. Great poise."
Niese had his brother, agent and a few friends in attendance. When he returned to his locker, he had several game balls and two lineup cards waiting for him as souvenirs.
"He performed extremely well. I was very impressed with the way he attacked them," Manuel said. "From all the things I've heard about him, he is a tremendous competitor, so I think he was anxious to get back out there and perform."
Niese even got his first hit, an infield single in the fourth.
Luis Ayala worked a two-hit ninth, completing New York's 11th shutout. The Braves have been blanked 14 times.
Scott Schoeneweis (2-4) took the loss, allowing a single to his only batter.
"Even though we're in first place, it's not over yet," Santana said. "We still have a long way to go. We have to protect our lead. We have to play better baseball. We have to do the little things."
It was the seventh time in 31 starts with the Mets that Santana left with a chance to win only to have the bullpen blow it. Five of those collapses have come in the ninth inning.
This was New York's second doubleheader in seven days and sixth this season, its most since playing eight in 1998. The Mets are 0-1-5 in twinbills. They were swept May 20 at Atlanta.
Niese became the youngest Mets starter to win since Bill Pulsipher on Aug. 26, 1995. Pulsipher was one day younger than Niese. ... Beltran is batting .429 with four homers, 12 RBIs and 15 runs during his 11-game hitting streak. ... Nursing a stiff back, Atlanta 3B Chipper Jones missed both games. He hopes to return to the lineup Sunday for his final chance to play at Shea Stadium, one of his favorite ballparks.