Reynolds, who was given a day off Sunday, smacked four homers in the three games in which he played at the Mets' new ballpark. That gives him as many long balls as his good friend, Mets third baseman David Wright, has all season at Citi Field.
"There's not a park that can hold him when he gets ahold of one," D-backs manager A.J. Hinch said. "He centered a lot of balls that obviously ended up over the fence in this series."
After taking batting practice before Friday's opening game, the D-backs thought homers would be hard to come by. Instead, they clubbed seven in scoring 20 runs during the series.
"I hit some in BP and they didn't come close," Reynolds said. "It's a big place. Like I said, I was lucky to run into four. I've definitely hit some this year at Chase [Field] and other places that wouldn't have come close to going out of here, so it's a give and take."
Reynolds and Miguel Montero hit back-to-back homers in the first inning to cap a three-run rally.
One inning later, after a Justin Upton single scored Gerardo Parra, Reynolds hit a two-run homer off starter Nelson Figueroa to put the D-backs up, 6-0.
"I've never faced Figueroa," Reynolds said. "I didn't even know what he had."
Giving a lead like that to ace Dan Haren almost ensures a victory, but the right-hander did not have his best stuff and struggled to keep the Mets at bay.
The Mets scored a run in the third, three in the fifth and Daniel Murphy hit a hanging breaking pitch into the upper deck in right in the sixth to pull New York to within a run.
"It didn't go quite as planned for me," said Haren, who improved to 11-6 on the year. "But I got the runs early and got it to barely hold up. Obviously the story was the offense and Mark swinging the bat and the bullpen coming in and closing the door."
The game-time temperature was 80 degrees, but it was extremely muggy and Haren appeared out of gas as the game wore on.
"I wish we had had an eight- or nine-run lead," Hinch said. "They shut us down and we didn't have a ton of opportunities after that. You don't want to get complacent when you get a six-run lead with Dan Haren. He wasn't perfect tonight, and they scratched and clawed their way back into the game, and we were fortunate to hold on."
Jon Rauch allowed one hit in a scoreless eighth and closer Chad Qualls retired the Mets in order in the ninth to pick up his 20th save.
Reynolds has 32 homers on the year, just two behind Albert Pujols for the Major League lead, but it's the four he has at Citi Field that will give him bragging rights over Wright. While Reynolds said he planned on texting his friend later that night to give him some good-natured ribbing, he also defended Wright against those who have criticized his performance here.
"Dave is just an all-around hitter, he's not really a power guy," Reynolds said. "He's a line-drive guy and he runs into them. He's a top-tier player. He's hit almost .330 and obviously it's not very good for his power numbers, this park, but at the same time he's finding gaps and I'm sure he's hit plenty of doubles this year."