The loss was the second straight for the D-backs, who had won their previous five, while the Mets snapped their second six-game losing streak this month.
Harvey, who entered the season ranked as the Mets' No. 2 prospect by MLB.com, set a franchise record for strikeouts in a debut. He allowed three hits and walked three before departing after 106 pitches with one out and D-backs on first and second in the sixth inning.
The D-backs were hoping that Harvey might be more than just a little nervous and that they would be able to take advantage of that.
"When you're facing a guy who's making his Major League debut, you're kind of licking your chops a little bit," D-backs outfielder Jason Kubel said. "But that wasn't the case today. Hopefully he would be a little amped and miss his spots and leave some balls out over the plate, but he just didn't do that."
Looking for a scouting report on Harvey, the D-backs turned to rookie third baseman Ryan Wheeler, who faced Harvey once in this year's Triple-A All-Star Game.
"I don't know if he was throwing 98 [mph] then, he was probably hyped up on some adrenaline today," Wheeler said. "He was tough."
And better than Wheeler had remembered.
"We knew he threw hard; we knew he had a hard slider," Wheeler said. "The changeup, I mean, I'd seen one changeup in the All-Star Game and it wasn't good, and today his changeup seemed to be on. So that was the best I could do on a scouting report. The only thing we knew was that he had a really good arm, and he showed that today."
The Mets helped Harvey settle in with a pair of runs in the first inning.
After Ruben Tejada and Daniel Murphy singled to start the game, Scott Hairston followed with a double to right-center that scored them both.
"I just wanted to make sure, first and foremost, I had to wait him out a little bit," Hairston said of D-backs starter Wade Miley. "I know last time I faced him I was a little impatient. He was locating pretty well today and he still pitched good overall. He's been consistent all year, so we knew we had to make him throw pitches and just capitalize on his mistakes."
The Mets added a run in the fourth, thanks to a one-out triple by Andres Torres and a sacrifice fly by Rob Johnson.
All three of the runs came off Miley, who allowed nine hits in 5 1/3 innings. The loss snapped the rookie southpaw's two-start winning streak, sending his record to 11-6.
"I was just getting behind guys early, in some 2-0, 2-1 counts and they had fastball counts and they were taking advantage of them," Miley said. "I didn't make quality pitches and it cost me. I just didn't have good stuff tonight, kind of battled a little bit. It's hard to have success when you're behind in the count."
Once Harvey left the game, the D-backs were able to put more runners on base, but only could get one of them in.
Justin Upton put the D-backs on the board in the eighth, with his sacrifice fly scoring Kubel, who drew a walk and was doubled to third by Paul Goldschmidt against Mets reliever Jon Rauch.
The D-backs left six men on base in the final four innings and had two on with two outs in the ninth with Kubel, their best hitter this year, at the plate.
"We had our opportunities, we were unable to capitalize on them," Gibson said. "We had some very favorable situations. Who could we have asked to have up with two guys on in the ninth inning? It was as good of a scenario as we could map out if you're going to be down."
Mets closer Bobby Parnell, though, fanned Kubel to end the game.