MIAMI -- Joey Lucchesi knew it immediately, thrusting his hands in the air and removing his cap as he stared at the scene down the left-field line at loanDepot park. Lucchesi had just thrown a ball to no one in particular, unaware that third base was unoccupied. As a result, a key run scored in what became a walk-off 4-3 Mets loss to the Marlins on Tuesday night.

“I just kind of felt a little embarrassed, you know?” Lucchesi said. “No one’s there and you throw it away.”

The play itself was an unorthodox one. With men on first and second base and no outs in the fifth inning of a tie game, Xavier Edwards laid a bunt down the third-base line. Lucchesi, third baseman Ronny Mauricio and first baseman Pete Alonso all charged, with Lucchesi and Mauricio arriving at almost the same time. Shortstop Francisco Lindor was covering second base and second baseman Jeff McNeil was at first, leaving third unoccupied.

That was the view from 30,000 feet, at least. Lucchesi saw things from a narrower angle until after he picked up the ball and almost collided with Mauricio, which didn’t dissuade him from throwing to third base anyway.

“I guess I kind of felt like someone was over there,” Lucchesi said. “I’m just going to own it. I made a bad mental mistake. It’s in the past. I’ve got to just learn from it and I’m going to move on.”

A consolation of the play was that left fielder Tim Locastro sprinted after the ball and fired to third, where Mauricio returned to the bag in time to tag out the trail runner. But the go-ahead run had already scored, and four innings later -- after Brandon Nimmo hit a game-tying two-run double in the top of the ninth -- the Marlins walked it off on Jake Burger’s RBI single.

“Mauricio called him off on it and obviously, the third baseman’s standing beside you,” Mets manager Buck Showalter said of the crucial play. “There’s nobody to throw [to] there. You’re just trying to get an out there.”

Lucchesi’s wild throw overshadowed what was otherwise another fine start for the left-hander, who held the Marlins to two other runs over 5 2/3 innings. For the second consecutive start, Lucchesi struggled to command his signature “churve,” but he managed to keep Miami mostly at bay through the combination of his sinker and cutter -- the latter a pitch he has worked to perfect since returning from Tommy John surgery last year.

“He’s a little funky,” Marlins shortstop Garrett Hampson said. “You don’t really see motions like that. I think that helps him be deceptive with his fastball. It’s only 90 or 92, but it doesn’t feel like that. It feels like it gets on you a little bit. You don’t pick it up as well.”

Through his two starts since returning to the Mets’ rotation, Lucchesi owns a 1.42 ERA. He’s been part of a strong fill-in crew of starters including David Peterson, Tylor Megill and José Butto; those four have combined to produce a 2.65 mark with 74 strikeouts in 74 1/3 innings since Aug. 27.

Realistically, most if not all of the four will play a role in next year’s pitching equation, serving as depth behind Kodai Senga, José Quintana and whoever the Mets acquire this offseason.

When called upon in that capacity, Lucchesi hopes to take the lessons from this season -- the good, the bad and the throwing-into-left-field-ugly -- with him.

“You make mistakes in life,” he said. “You’ve just got to make sure you learn from them and then not do them again.”