NEW YORK -- The demands of the playoff races had winning essential Tuesday night, and Johan Santana's presence underscored the importance.

"We had our pitcher going," Mets manager Jerry Manuel said.

Because of their 6-2 victory, the first in four games against the Cubs this season, the final five have retained full consequence for the Mets. New York was victorious for the first time in four games, maintained its one-game lead in the National League Wild Card race and reduced its deficit in the NL East to a more manageable 1 1/2 games.

The Mets never put in words what losing would have meant. But it was clear when Jose Reyes said, "This is the biggest win of the year for us," and Manuel said, "We had to win tonight."

The Mets couldn't afford to lose another Santana start. They had lost his start against the Braves 10 days earlier. The margin for error had begun to narrow for another misstep.

Santana seemed intent on avoiding that outcome, particularly after a four-run rally -- which included Reyes' three-run triple, his 200th hit this season -- against losing pitcher Chad Gaudin in the sixth produced the lead. Santana had allowed two runs -- one in the second inning and one in the third -- on four well-struck hits, three of them doubles. He allowed a walk in the sixth. But he struck out two in the clean seventh and two more in the eighth -- he finished with 10 strikeouts -- before he allowed his seventh hit and second walk.

"He got nasty when we got ahead," his catcher, Ramon Castro, said. "Like he was meaner. I didn't worry when he had runners on base. He wanted to win so much, I knew he wouldn't let them score."

Santana threw 125 pitches, the most in his career.

"He wound up about 100 short," Manuel said.

There was no thought to starting him on short rest Saturday against the Marlins. And now there's less of a chance. But when he does pitch Sunday -- if the Mets need a victory to secure a place in the postseason, there will be no pitch count.

"I didn't even know I had that many pitches, to be honest with you," Santana said. "All the intensity in the game and everything that we went through, I was just out there trying to help. But you do what you have to do to do your job. This was the game I was supposed to pitch and win. That's why I'm here. I hope the next one is the same way."

The victory, his 15th, was the Mets' ninth in his 10 most recent starts. He hasn't lost in 16 starts and the team has won 12 of them.

Mets heroes were many in the victory that moved their season from the brink. And they were hailed heartily by those who gathered at Shea Stadium in hopes of witnessing that needed reversal.

Reyes was saluted in the sixth after his key triple. David Wright had been toasted an inning earlier when his bases-loaded single performed CPR on the Mets' postseason chances. And, of course, Santana was embraced as he walked to the dugout, having pitched effectively for eight innings and fiercely in his final three.

But the player whose turn at-bat -- and two-out base on balls -- in the fifth inning were so critical to the Mets' get-well win was lustily booed almost throughout the otherwise rousing evening at the ballpark.

Luis Castillo was a hero, too, though his contribution went virtually unrecognized by the masses who had come to Shea to scorn, not praise, him.

After the game, Manuel spoke of the need to do "the little things" when the opponent is particularly challenging.

This opponent already had clinched the best record in the National League and home-field advantage throughout the playoffs. The Cubs qualified as a genuine challenge, and Castillo had done the little-big thing that afforded Wright the opportunity to be a hero. Regardless, Castillo was jeered as he approached the plate for his at-bats in the sixth and eighth innings and after he was retired.

"Nobody noticed" what he had done in the fifth, he said later, his expression a sad smile.

Castillo now is in a class with Doug Sisk, Armando Benitez and -- earlier this season -- Carlos Delgado, a near anti-hero despite his uniform. He is booed on general principle.

"I'm getting better," Castillo said Tuesday. "But they boo me."

Without his walk, Wright would have led off the sixth inning. And who knows what that would have prompted? Instead, Wright pulled a soft-line drive to left field for his first hit in 12 at-bats with the bases loaded and the runs that overcame the inertia that had suffocated the batting order for four innings tied the score. The Mets had three baserunners in the first four frames against left-handed Sean Marshall, and they were jumping at his offspeed pitches.

"You can't score the third and fourth runs before you score the first two," Santana said, seemingly troubled by the treatment afforded Castillo. "That was a big walk."

"I was begging for a chance to hit," Wright said. "I wanted the bat in my hand with the game on the line to help this team get to the next level."

His swing produced the 121st and 122nd RBIs of his season. Among Mets players, only Mike Piazza -- 124 in 1999 -- had driven in more runs in a season. And Wright's campaign has five more games remaining.

Before Wright's clutch knock in the fifth, before Castillo's walk, came Santana's bizarre infield hit that put runners on first and second. Reyes struck out for the second out, and that's when Castillo worked a walk to extend the inning. With Nick Evans on first base, Santana hit a broken-bat ground ball to the first-base side of the mound. Marshall might have initiated a double play. But the bat head came between him and the ball and, 25 feet farther, the bat hit the ball and made it unplayable.

It was rightfully scored a single and appropriately seen as a signal.

"He must be living right," Ryan Church said.

But Pedro Martinez was certain it had greater significance.

"You get a ball like that," he said, "and you better win that game. You get that ball and it's a good sign. But you have to win the game."