DENVER -- The ninth inning unfolded perfectly Tuesday night for the Colorado Rockies.

They had the winning run on second base and Nolan Arenado batting. Who better to be at the plate in a clutch situation?

Arenado's single with no outs gave the Rockies a 5-4 win over the New York Mets. It was his second walk-off hit of the season, the fifth of his career, and it gave Arenado four RBIs for the game, boosting his major-league-leading total to 95.

Charlie Blackmon, who ended the top of the ninth inning with a stunning catch, led off the bottom of the ninth with a six-pitch walk against Hansel Robles (6-2).

Blackmon broke for second on Robles' 3-2 pitch to DJ LeMahieu. Shortstop Amed Rosario, the Mets top-rated prospect who went 1-for-4 in his major league debut, took a step toward second base, and LeMahieu's hard grounder went off his glove for an infield single.

Arenado, who put the Rockies ahead 3-2 with a three-run homer in the sixth, looped Robles' 0-2 fastball to center to give the Rockies their third walk-off victory this season.

"I want those at-bats in those moments," said Arenado, who led the majors in RBIs each of the past two years and is batting .452 (47-for-104) this season with runners in scoring position. "I want to hit in them. Obviously, I don't like failing in them, but I feel as comfortable as you can be in those moments."

Blackmon made a leaping catch in center of Asdrubal Cabrera's long drive to conclude the Mets' ninth. Blackmon banged into the wall and went down but held the ball.

"I knew it was hit really well, so I put my head down for a few steps and tried to make up some ground," Blackmon said. "I got close enough to where I thought I might be able to make a play on it, so I went for it."

Mike Dunn (3-1) worked a scoreless ninth inning because closer Greg Holland was unavailable. Holland sustained a small cut on the top of his right index finger doing dishes, and the cut opened while he was warming up.

Jay Bruce lofted a home run off the right field pole to open the eighth and give the Mets a short-lived 4-3 lead. The Rockies tied the score in the bottom of the eighth with a hit nowhere near as majestic as Bruce's.

Mark Reynolds and Gerardo Parra opened the inning with singles. Trevor Story grounded into a force play that put runners on the corners. Carlos Gonzalez brought in a run with a slow roller to third that he beat out for a single, extending his hitting streak to 10 games.

Pat Neshek was charged with a blown save in his Coors Field debut with the Rockies. He struck out pinch hitter Jose Reyes with one out in the seventh inning, but catcher Ryan Hanigan was charged with a passed ball on the third strike. Michael Conforto singled, sending Reyes to third.

Reyes scored to tie it at 3 on Cabrera's sacrifice fly that wasn't hit that deep. Blackmon might have had a play at the plate, but his throw went straight to the ground and assuredly became a blooper-reel staple.

"I couldn't get the ball out of my glove cleanly," Blackmon said. "So, at that point, I decided that to make a throw to the plate wouldn't result in an out. It could only result in the runner (on first) moving into scoring position. So, I tried to abort that throw to the plate, and I got some really good down angle on that ball."

Mets starter Steven Matz, who entered the game 0-4 with a 14.18 ERA in his past four starts, held the Rockies hitless for 4 1/3 innings. The Rockies finally scored off him in the sixth. Blackmon led off with a single, DJ LeMahieu doubled -- the ball landing just inside the left field foul line -- and Arenado hit an opposite-field homer to right center.

Matz gave up six hits and three runs in five-plus innings. He got 11 outs on ground balls.

"I think I had more life on my fastball," Matz said. "I was getting a lot of ground balls and mixing it up and keeping the off-speed down in the zone."

Yoenis Cespedes doubled home a run in the first against Rockies starter Jeff Hoffman. In the sixth, Cespedes led off with a single, and Bruce turned on a changeup and lined it into the right field corner to put New York ahead 2-0.

Hoffman was 1-2 with an 11.79 ERA in his three previous starts, but he rebounded to give up just those two runs and five hits in six innings.

"There was a heavy volume of fastballs," Rockies manager Bud Black said. "The curveball-slider really didn't come into play. He did throw some changeups, which was I was really proud of him. But it was heavy fastball, heavy fastball command, heavy fastball movement."

NOTES: Rockies C Jonathan Lucroy, acquired Sunday from Texas, was activated but was scratched because of a stomach illness. ... Rockies RHP Chad Bettis (testicular cancer) is scheduled to pitch six innings or 90-95 pitches Thursday for Triple-A Albuquerque in his fifth rehab appearance. ... Rockies LHP Jake McGee (mid-back strain) underwent an MRI exam Monday that showed no structural damage. He will play catch Wednesday and is eligible to be reinstated Sunday. ... Rockies RHP Jordan Lyles was released after being designated for assignment Saturday. ... Colorado C Tony Wolters was optioned to Triple-A Albuquerque. ... Mets CF Juan Lagares (fractured left thumb) began a rehab assignment with Double-A Binghamton and went 2-for-3 while playing five innings in center field. ... New York RHP Robert Gsellman (strained left hamstring) threw three scoreless innings in his second rehab start for Binghamton.