NEW YORK -- As Wilmer Flores stepped to the plate in the second inning Monday, he doffed his helmet to the Citi Field crowd, then glanced back at Mets pitcher Jacob deGrom and winked.

“We have a really good friendship. I just wanted to say hi,” Flores said after the game, a 3-1 Mets win.

deGrom said he didn’t notice the friendly gesture.

"I don't think my eyes are that good. I didn't see him. But that's a little bit annoying,” deGrom said, smiling in the postgame clubhouse.

The fans behind Flores were mostly on their feet, saluting him for all he accomplished during six years in Flushing. Then a switch flipped.

“Strike him out, deGrom!” one fan yelled, as others around him laughed.

Ever businesslike, deGrom did his part, inducing Flores to ground out to shortstop. But it was nonetheless a warm moment for Flores, a fan favorite for the better part of this decade.

Flores turned the tables on his former teammate in the fifth, when he led off the frame with his eighth homer -- and his first against a right-hander -- of the season.

deGrom conceded that if he had to allow a homer, “I guess I probably would have picked Flo. That's a little frustrating, though."

Asked about his penchant for coming through in the clutch when the spotlight is on him, Flores said, “I don’t think it’s about moments. I’m up there with a plan, which is hit the ball hard -- wherever it’s pitched. As a hitter, you go up there with a plan. I had a 3-1 count and I didn’t miss the pitch I was looking for.”

Before the game, Flores exchanged hugs and handshakes with Amed Rosario, Todd Frazier and others around the batting cage, all of them his teammates last season. The Mets also had a scoreboard tribute to Flores, who watched his highlight reel with former teammates Michael Conforto and Brandon Nimmo.

Rather than tender Flores an arbitration contract that likely would have exceeded $4 million, the Mets parted ways with their longtime utility infielder in November. The D-backs subsequently scooped him up on a contract worth $4.25 million guaranteed.

Flores has made good on it, entering Tuesday batting .320/.362/.498 with eight home runs in 76 games. Flores’ ability to hit left-handed pitchers is what made him so valuable in Flushing, along with his consistent ability to come through in clutch moments. Over six seasons, Flores racked up a franchise-record 10 walk-off RBIs.

The most impactful of those was the homer he hit against the Nationals on July 31, 2015, two days after the Mets agreed to trade him to the Brewers -- a deal that fell apart over medical issues, but that prompted Flores to weep on the field while a game was taking place. Flores’ walk-off spurred the Mets to a series sweep of the Nationals, which in turn propelled them on a run that ended with the National League pennant.

“There were a lot of moments, but I think playing in the World Series is a moment that I’ll never forget,” Flores said. “I have to thank [the Mets] a lot. They gave me the opportunity to play for the first time, and I appreciate them.”

Mostly as a part-time player, Flores hit .268 with 68 home runs in six seasons in New York, embodying many of the highs and lows that defined the Mets franchise during that time.

Until Monday, however, he had never faced deGrom.

“[deGrom] has stuff and command. When a pitcher has those two things, it’s going to be tough,” Flores said. “You know it’s going to be a battle, and he won the battle today.”