MIAMI -- Facing the possibility of a second consecutive extra-inning game, Garrett Cooper stepped to the plate and called ballgame.

Cooper knocked a two-out, two-run walk-off homer to give the Marlins a 3-1 victory over the Mets on Saturday at loanDepot park. He stayed hot at the plate, sending a full-count cutter from Drew Smith over the left-center wall. Cooper has gone deep in three straight games for the first time in his MLB career.

Miami’s second walk-off win of the season prevented a potentially frustrating defeat. Hours before, manager Don Mattingly compared his club’s precarious pitching situation to walking a tightrope over the Grand Canyon. The previous evening, the Marlins used 10 pitchers in a 12-inning loss, setting into motion a series of roster moves to protect the bullpen.

“That was huge, and I tried to save this bullpen, because last night's game we were running on not much sleep the night before, we got in pretty late,” said Cooper, who went 3-for-4. “I think everybody was pretty tired, and you saw using our bullpen all of last night [that] we didn't want to go to extra innings again.”

Cooper wasn’t the only one lending a hand to the taxed bullpen. Pablo López did his part with seven scoreless innings, though the game got off to an ominous beginning. López needed 21 pitches to escape the first unscathed, striking out Wilfredo Tovar with the bases loaded. From that point on, the righty retired 19 of the final 21 batters he faced and allowed just one more runner in scoring position.

López recorded his first quality start since April 30 in Washington, pitching a combined 14 1/3 innings in his last three outings. While he hasn’t been able to go deep into games, he has limited hard contact. His average exit velocity of 85.2 mph entering Saturday was third best in the Majors, behind only Wade Miley (84.3) and Ryan Yarbrough (84.4) (min: 100 batted balls).

"It's something you can embrace, it's something that you can use as motivation," said López, who threw 90 pitches. "You want to be the guy that goes out there and helps the bullpen out, you want to be the guy that goes out there and can go deep into the game, you can execute pitches, you can get out of jams if you get into jams. I try to embrace what happened last night. I have an opportunity here to be that guy, and I was really excited, and really happy with how it went because that's what I really wanted to do today."

With the Marlins ahead 1-0, a missed inning-ending called strike three by home-plate umpire Alfonso Marquez kept a Mets rally alive in the eighth. Dominic Smith sent the next pitch from southpaw Richard Bleier into right field for the game-tying RBI single.

Bleier, who was brought in to face the left-handed-hitting Smith, had begun to walk off the mound thinking he had helped teammate Anthony Bass out of a jam with two runners on. Following Smith’s knock, Bleier was visibly frustrated, so much so that pitching coach Mel Stottlemyre Jr. came to the mound to give him time to calm down. He struck out the next batter to limit the damage.

Yimi García pitched a scoreless ninth to set up Cooper’s heroics. He, Bass and Bleier also appeared in Friday’s game. Setup man Dylan Floro was warming up in case the game went to extras. Ross Detwiler, Adam Cimber and Zach Pop likely were unavailable after pitching on consecutive days.

Prior to the game, Miami selected the contract of Shawn Morimando from Triple-A Jacksonville as a safety net in case of a short start. Morimando, who last appeared in the Majors in 2016, was built up to 80-90 pitches.

“We weren't really worried about the number of innings, but to keep sending those guys out there, you'd like to stay away from everybody,” Mattingly said. “Pablo did a great job to get us back there. And then to be able to end it there, big win for us. Two-game swing, and then to have a chance to win a series.”