The 24-year-old went 1-for-4 with a double, a walk and a run scored in his International League debut as Buffalo rallied to beat Norfolk, 8-7, on Tuesday.
"I felt comfortable playing up here and it was good to get that first win," den Dekker said. "It was nice to be with the team. Every time you move up a level, there are some [nerves], but I'm just trying to stick to my approach. I felt good."
Batting first in the Buffalo lineup, den Dekker walked in his first at-bat, but he was thrown out trying to steal second with Corey Wimberly at the plate.
He grounded out to end the second inning and he struck out swinging for the final out of the fourth. In the seventh, den Dekker doubled to right field, advancing to third base on outfielder Jai Miller's errant throw, and he scored on Wimberley's ground ball to center field. He struck out in the ninth.
"It was off a curveball," den Dekker said of his first Triple-A hit. "It was down the right-field line and I was able to stretch it into a double. The throw bounced off my leg and I got to third base."
Selected by New York in the fifth round of the 2010 Draft out of the University of Florida, the Mets' No. 15 prospect drew rave reviews in his second look at the Eastern League.
He led the league with a .340 batting average prior to his promotion, and he recorded 33 extra-base hits and 29 RBIs in 58 games. The numbers were a big improvement from last season, when he hit just .235 in 72 outings with the B-Mets following a midseason callup by St. Lucie.
"I'm just going to keep playing hard and not worry about goals," explained den Dekker, who said he is focused on getting good pitches to hit early in his at-bats. "I'm taking it one day at a time. It's exciting, but I'm not thinking about [the Majors]. I'm playing against some veterans and guys with experience and I'm excited about that."
Tuesday's win capped a busy 24 hours for the center fielder, who learned about the promotion in a phone call from Binghamton manager Pedro Lopez on Monday night.
Den Dekker then made the three-hour drive to Buffalo this morning to be reacquainted with some familiar faces.
"It wasn't too bad, it was a good ride," he said. "I worked with [hitting coach] George [Greer] last year in St. Lucie and [manager] Wally [Backman] in Binghamton, so I'm comfortable around them. I've played with some of the guys in Spring Training and in the past."
On Tuesday, Pedro Beato (3-0) earned the win, allowing one hit and striking out three batters over 1 2/3 innings. Buffalo starter Garrett Olson yielded four runs on five hits and two walks while fanning three batters over 4 1/3 frames.
Left-hander Zach Phillips (0-1) blew his fourth save of the year and ended up with the loss. He surrendered three runs -- one earned -- on two hits and a pair of walks over 1 2/3 innings. He struck out three batters.
Norfolk starter Jason Berken gave up five runs -- two earned -- on three hits and two walks while punching out six batters across four innings, but he did not factor in the decision.