Syndergaard threw eight sharp innings and the light-hitting Mets got a break when Cincinnati ace Johnny Cueto suddenly lost the strike zone, edging the Reds 2-1 Friday night.
The Mets returned home from a 1-7 road trip in which they totaled 11 runs, and won despite getting only two hits.
"We've got the pitching," manager Terry Collins said. "There's nothing wrong with our pitching. We've just got to give them some help."
With the Mets set to call up prized prospect Steven Matz this weekend and go to a six-man rotation, Syndergaard (3-4) was in control. The 22-year-old rookie said he had no trouble with adding an extra starter, especially if it meant pitching deeper into games -- and deeper into the season.
"My ultimate goal is to be able to pitch in October," Syndergaard said.
The Reds lost for the third time in nine games. They got to their New York hotel at 4:17 a.m. after a rain-delayed, 13-inning win at Pittsburgh.
Curtis Granderson launched a leadoff homer into the second deck on Cueto's third pitch.
"He hits home runs in clumps," Collins said after Granderson connected for the fourth time in six games.
It was 1-all in the fifth when Dilson Herrera tripled with two outs. Cueto (4-5), pitching with eight days' rest to give his aching right elbow some extra rest, hadn't walked a batter all game until walking Granderson, Eric Campbell and Lucas Duda to force home the go-ahead run.
Duda had already struck out twice, and had fanned 10 times in 15 career at-bats against Cueto, before hanging in after two quick strikes. Catcher Brayan Pena twice went to the mound to talk to Cueto once the count went full.
"Things happen. I was too much careful in that inning. I did not want to leave the ball in the middle," Cueto said through a translator.
"I was trying to trick them," he said.
Syndergaard gave up five singles, walked none and struck out five in the longest of his nine starts in the majors. He hit 99 mph with his fastball in the first inning, mixed in his changeups and curves against an aggressive lineup and won for the first time in five starts.
The Mets' infield backed him all night. Shortstop Wilmer Flores, third baseman Ruben Tejada and Herrera at second and Duda at first each made nice plays, and catcher Kevin Plawecki caught a runner trying to steal.
Jeurys Familia pitched a perfect ninth for his 21st save in 23 chances.
Collins said before the game that Granderson might be able to ignite the team. He was right, as Granderson hit his 32nd career leadoff home run and fourth this season.
Brandon Phillips singled in the third, and has hit safely in all 30 games he's played on the road against the Mets.
EVEN IN NEW YORK
The loss left Cincinnati 148-148 when visiting the Mets over the years at the Polo Grounds, Shea Stadium and Citi Field.
Reds: All-Star C Devin Mesoraco will have surgery in New York on Monday to fix an impingement in his left hip. He hasn't caught since April 12 and has been on the disabled list since May 25.
Mets: Tejada exited soon after being hit in the left elbow by a pitch from Cueto. X-rays were negative, and Tejada has a bruise. Collins said he might need a day to recover.
Reds: Rookie RHP Michael Lorenzen (3-2, 3.56) has won two straight starts. He's allowed more than three runs just once in nine big league starts.
Mets: RHP Matt Harvey (7-5, 3.18) has given up a total of one run in his last two outings. That followed a string of four rough starts in a row.
Newly drafted Kris Porzingis and Jerian Grant of the New York Knicks threw out ceremonial first balls. Both tosses made it to the plate on the fly.
The Mets held a pregame moment of silence for former owner Nelson Doubleday Jr. and former outfielder Darryl Hamilton.