NEW YORK -- Homer Bailey was at his best with runners on all around him.
"Early on I was a little off and once I kind of got loose then everything started flowing pretty good," Bailey said.
Ryan Ludwick added an RBI single to help the NL Central leaders move a season-best 10 games over .500 at 37-27.
Bailey (5-4) worked his way through several early jams and took advantage of the ample dimensions at Citi Field. Though the fences were brought in before this season, David Wright hit two of four Mets drives that were caught within steps of the wall.
"Homer was outstanding," Reds manager Dusty Baker said. "He was dealing tonight. He's been pitching well. He got roughed up I think a couple starts before this, but other than that he's been very reliable."
Bailey was hit hard by the Mets twice last year in his only previous outings against them. This time he allowed six hits and one walk while striking out three to improve to 4-1 in his last six starts.
Aroldis Chapman tossed a hitless ninth for his eighth save.
New York starter Jonathon Niese (4-3) made one big mistake to Bruce during seven otherwise effective innings. He struck out seven and walked one but lost for the first time in six starts at home this season.
The left-hander was 2-0 with a 1.75 ERA in his previous four outings overall and had not allowed an earned run in 13 innings this month before Bruce connected in the first.
"I don't regret throwing the pitch. I regret hanging it on the inside part of the plate," Niese said. "Hindsight's 20-20. I probably should have thrown a fastball up and in and been done with it. Maybe he would have swung through it, maybe not. But that's baseball. It's one pitch, one mistake, cost me the game."
Zack Cozart opened the game with a single and Wilson Valdez followed with a bunt single. Niese struck out Votto looking and was one strike from escaping unscathed when he dropped down almost sidearm for an 0-2 breaking ball that he wanted down and away against Bruce.
The pitch hung right over the middle of the plate, however, and Bruce hammered it deep into the right-field stands for his team-leading 15th homer.
"He made a mistake with it. I didn't miss it," Bruce said. "Other than that, he did really well."
It was Bruce's second homer in two nights at Citi Field. The first one was an inside-the-park shot Friday.
"I'll take `em both, that's for sure. But it's definitely nicer to trot around," Bruce said. "But at the end of the day it's the same result, so however you can get 'em you've got to get `em."
Bruce's opposite-field drive Friday night left Mets outfielder Jason Bay with his second concussion in two calendar years after he crashed into the wall trying to make a difficult catch. The oft-injured Bay was placed on baseball's seven-day disabled list for concussions Saturday, and manager Terry Collins said he expects the left fielder to be sidelined longer.
Bay had just recently returned to the lineup after missing six weeks with a broken rib.
Consecutive doubles by Daniel Murphy and Wright put the Mets on the board in the bottom of the first, but Bailey limited the damage. New York put runners at the corners with nobody out the next inning and failed to score.
That began a string of eight straight outs for the right-hander before the Mets put their first two batters on in the sixth. Once again, Bailey held firm and retired three in a row to preserve a three-run cushion.
"He dialed it up some," Baker said. "His fastball was 90, 91 (mph) and then with runners on base it was 93, 94 (mph). That's what the good ones do."
Bruce was hit by a pitch to start the fourth and scored on Ludwick's single.
Cincinnati goes for a three-game sweep Sunday with ace Johnny Cueto (7-3, 2.46 ERA) on the mound against RHP Chris Young (1-0, 3.38). ... Reds 2B Brandon Phillips, who had homered in a career-best three consecutive games (nine RBIs), went 1 for 4 with a single. Phillips wore a microphone during the game for the Fox broadcast. ... OF Chris Heisey missed his second straight game with a mild left groin strain. Baker said Heisey definitely needed another day, maybe more. ... 3B Scott Rolen (strained left shoulder) was scheduled to complete a two-game rehab assignment with Triple-A Louisville on Saturday night and rejoin the Reds for Monday night's game in Cleveland. Baker said the timeline is not as definitive for LHP Bill Bray (strained left groin), also rehabbing at Louisville. ... Cincinnati and Miami are the only teams to use only five starting pitchers this season.