He also struck out nine in the process and now owns a 13-7 record to go along with a 2.91 ERA and a 1.12 WHIP.
A pair of National League wild card contenders will meet Monday night, when the Mets host the Miami Marlins in the opener of a pivotal four-game series at Citi Field. NY (68-64) remained 2 1/2 games behind St. Louis for the league's second wild card.
"He kind of thinks he's a lot better today and that's why we think tomorrow we'll know a lot more", Collins said. The bad news is that seven of their games against winning teams come this week, when the Miami Marlins and Washington Nationals come to town to wrap up the Mets' ten game home stand.
The Marlins scored just one run in losing the final two games of a three-game series to the Padres.
Granderson, batting for Lugo, connected against Koehler (9-10) for his second career pinch-hit homer leading off the sixth, extending the Mets' lead to 4-2 with the club's ninth pinch-hit homer this season.
De Aza added an RBI single later in the inning off Dustin McGowan. RHP A.J. Ramos was OK after crashing into Reyes on a play at the plate Monday night, Mattingly said.
Granderson, who stayed in to play right field, launched a two-run shot in the seventh.
Reyes singled leading off the first and Cabrera went deep on the next pitch.
DeGrom later said he sees from video that he is again falling off too far toward first base, which raises his arm slot and makes his pitches flat in the strike zone.
Reyes and Cabrera got on base seven times in 10 combined plate appearances from the top two spots in the lineup.
Slumping slugger Jay Bruce, who started over Granderson, doubled later in the first and scored on a two-out single by Wilmer Flores that gave the Mets a 3-2 lead.
There was a point when Collins actually stopped in Port St. Lucie on an off-day after playing in Miami, they said, to talk with him.
The right-hander has lost two straight after going 3-0 in his previous six starts. The Mets need to try and get one of those two games and pick up wins in the other two, where they have more favorable pitching matchups with Bartolo Colon and Matz opposing David Phelps and Jose Urena respectively.
Marlins: LHP Adam Conley (finger tendinitis) began a throwing program in Florida.
Following Sunday's loss, Mattingly, tongue presumably planted firmly in cheek, said he might follow in the footsteps of his former manager, the late Billy Martin, and get creative in hopes of snapping the Marlins out of their slump. Due to Steven Matz's slight delay in activation from the disabled list and the choice to skip Jacob deGrom tonight, the Mets will send Rafael Montero and Seth Lugo to the mound to start the series. 2B Neil Walker sat out his third straight game with a stiff back.
"Sometimes those little adjustments like that can throw a pitcher off whack", his Triple-A manager, Wally Backman, told the Las Vegas Review-Journal. "That situation is what it is, and I don't have anything else to say except we hope that those flights keep going".