Den Dekker, who had a career-high three hits, scored the go-ahead run in the eighth inning, and the Mets beat the Marlins 4-3 on Wednesday night.
"The guys were back, and I saw that side of the field open," said den Dekker, who got on base to lead off the inning.
Kirk Nieuwenhuis hit a two-run home run for the Mets, who won two of three in the series with the Marlins and lead the season series 10-6.
"The Mets have played us tough and they've hit our pitchers," Marlins manager Mike Redmond said.
Miami's Giancarlo Stanton homered for the third consecutive game to give him 36 on the season and bring the Marlins within 4-3 in the eighth after the Mets took a two-run lead in the top half of the inning.
Den Dekker led off the eighth with a single off Mike Dunn (10-6), who also allowed a hit to Lucas Duda. Dunn was replaced by Bryan Morris, who immediately allowed an RBI double to d'Arnaud to right field to give the Mets a 3-2 lead. Herrera's groundout then scored Duda.
Jacob deGrom allowed one run and six hits in six innings for the Mets. He struck out six, walked two, and left with a 2-1 lead.
Marlins starter Tom Koehler struck out a career-high 10 batters in seven innings and allowed two runs, five hits, and four walks.
"I felt good, but unfortunately personal results don't really matter right now when we're trying to go on a little bit of a run here and win ballgames," Koehler said. "I would have much rather have got rocked and we won the game."
The Marlins tied it 2-2 in the seventh inning. Adeiny Hechavarria doubled to deep center field off reliever Buddy Carlyle, and lefty Dario Alvarez came in to face Christian Yelich, who singled to right to score Hechavarria.
Miami opened the scoring in the third with an RBI single by Casey McGehee. Nieuwenhuis' third home run of the season gave the Mets a 2-1 lead in the fourth. The Mets are 14-2 this season when Nieuwenhuis starts.
"I knew I hit it well, but in this park you never know," Nieuwenhuis said.
Juan Lagares led off the game with a single for the Mets, stretching his on-base streak to six consecutive plate appearances. He finished the game 2 for 5.
A day after Mets captain David Wright had three hits to break out of a 7-for-50 skid, he struck out four times and went 0 for 5.
The Marlins and Mets are both off on Thursday. Miami will host Atlanta for a three-game series beginning on Friday with RHP Jarred Cosart (3-1, 1.64) on the mound against Braves RHP Aaron Harang (10-9, 3.64).
MAKING A CASE FOR ROOKIE OF THE YEAR
DeGrom, who has a 7-6 record in 19 starts, leads National League rookies with 112 strikeouts and a 2.87 ERA.
"It would be a tremendous honor for the whole organization," Collins said of deGrom's chances to be the NL's top rookie. "The guys that helped this kid along the way, the fact that he's come up with really no buildup. When he got here he was going to go to the bullpen. We had an injury and now we can't get him out of the rotation, looks like he's going to be in it for a long time. Orel Hersheiser can tell you, a very similar thing happened to him. He came to the big leagues as a reliever, got a chance to start, and he ended up being one of the best pitchers in baseball."
Stanton is one of four players to have more than one streak of at least three games with a home run. The Marlins have homered in six straight home games.
Yelich has a 12-game hitting streak at Marlins Park and is hitting .500 (25 for 50) during that stretch. McGehee extended his hitting streak to seven games.