NEW YORK -- Uncertainty veiled Shea Stadium on Saturday even before darkness hit. From the moment the Mets realized that they would lose the first game of their twinight doubleheader -- the game that Johan Santana started, and so the game that they were supposed to win -- the rest of the night seemed coated with trouble.

The Phillies had already won, as Shea's giant outfield scoreboard confirmed. And so Mets rookie Jon Niese, with three big league innings to his credit, faced the unenviable task of beating the Braves. If he won, the day could be saved. If he lost, many of the accomplishments of the previous few weeks would come crumbling down.

"We can't afford people to come here and take two games like that," outfielder Carlos Beltran said.

So Niese, a rather unlikely savior, ensured that the Braves would do no such thing. Niese's eight shutout innings gave the Mets a 5-0 win over the Braves, not three hours after their rivals had stolen a 3-2 victory in the matinee. Night fell, and there was music playing in the home clubhouse instead of silence. There was hope instead of gloom.

"We got a split -- that's the bottom line," manager Jerry Manuel said. "And Johan pitched a good game, but this kid here was obviously a little better."

Niese stayed strong where Santana had crumbled, breezing through the eighth inning as easily as he had the previous seven. In only his second career start -- and his first since surrendering five runs over three innings on the night after Labor Day -- Niese allowed six hits, striking out seven batters and walking two.

Sporting a curveball that Jose Reyes called "one of the best I've ever seen from a lefty," Niese threw 75 of his 116 pitches for strikes and eliminated the need for a lengthy bullpen outing. He did, in short, everything that the Mets needed him to do.

"I think every kid in America dreams about that," Niese said.

Helping his cause was the Shea Stadium crowd, which gave Niese one standing ovation after the seventh inning, and another following his encore in the eighth. They chanted his name. They wouldn't stop cheering. And Niese made sure to listen.

"How can you not?" he said. "It's just a dream come true for any pitcher."

All pitchers, according to Niese, have another dream, too: early offense. And the Mets provided precisely that, scoring four times over the first two innings.

David Wright led the initial outburst, connecting on a two-run homer in the first inning that scored Ryan Church. Beltran then singled and scored, and Reyes also homered in the second inning. By the time the Mets scored again -- on Beltran's solo shot in the seventh -- the Mets knew what Niese was going to give them. And they knew that all the worries over Santana's wasted outing were perhaps a bit unfounded.

Santana certainly did not pitch poorly in Game 1, blanking the Braves for seven full innings. But he stumbled off the mound in the eighth, serving up two straight singles to open the inning and swinging the bullpen door wide open.

Scott Schoeneweis entered and loaded the bases, before Brian Stokes -- so critical to the bullpen's revitalization in recent weeks -- allowed a game-tying single on the first pitch he threw. Santana had lost his win, and three batters later, the rest of the Mets had all lost theirs.

"You cannot let just one game take you down," Santana said.

And so the team rallied. The Mets struck quickly and thoroughly in Saturday's nightcap, knocking Braves starter Jo-Jo Reyes out of the game after two innings.

The homers of Wright, Reyes and Beltran ensured that the Mets would salvage something from this day, that Niese would record his first career victory, and that the 54,705 paid ticket holders -- many of whom left during the second game -- could drive back home with a satisfied smirk. No matter how the Phillies performed, the Mets knew they had at least half an answer.

"I really don't pitch to where we're at in the standings," Niese said. "I just go out and execute a pitch, and if everything goes right, if everything goes to plan, we get a win."

Everything went according to plan, of course, and Saturday stayed neutral. Had the Mets lost two games to the Braves, they would have given the Phillies every reason to believe that they were on the verge of falling. Had they swept, they would have screamed out reasons why this race is all but over.

Instead, since they split, the manner in which they split did not matter. They salvaged something from a seemingly dark day, after Santana lost the game that even Manuel admitted he expected to win.

"Baseball's a funny game," was how the Mets manager described it, shaking his head following the matinee.

Then came the nightcap and then came Niese.

"It's just a funny game," Manuel reiterated after the second game.

Only this time, he was actually laughing.