NEW YORK -- Before the Mets’ finale against the Angels, the pregame musings of manager Buck Showalter primarily centered on the impact of the de facto bullpen game in the previous night’s contest. Because starter Carlos Carrasco was unable to escape the second inning, a slew of relievers had to shoulder the load in the loss, which put pressure on how to configure the roster down the road.

“Sometimes people say, ‘Why didn’t I bring this guy in?’ Well, you have all these different factors,” Showalter said before Sunday afternoon's walk-off 3-2 win over the Angels. “But quite frankly, it all comes off the fact that you have short starts. You have to get deeper into games, then, those things are pretty easy to maneuver.”

David Peterson apparently heard his manager loud and clear. The lefty, who hadn’t made it past the fifth inning in a start since July 8, gifted the Mets a lengthy outing. Peterson put together the definition of a “quality start,” tossing seven innings of one-run ball, allowing three hits and striking out eight (with three walks).

It was just the fourth time in his career that Peterson made it through seven innings, and the first time he had completed the feat in front of the Flushing faithful.

“He’s quietly been a real competitive force,” Showalter said of Peterson's performance. “But that was the key of the game -- his outing. Regardless of everything else that could be talked about, we needed a starter to get deep into the game, and Pete dialed that up for us.”

Peterson left it all on the mound while working to fill up the zone, throwing 65 of his 104 pitches for strikes. He had a good handle on his five pitches, which were each thrown at least 12% of the time. Peterson also produced 12 swings-and-misses, two short of his season-high total, with seven coming on four-seam fastballs.

“I would say, in-game, that’s one of the best I’ve felt this year,” Peterson said. “No doubt. It felt good to get deeper into the game, get over 100 pitches, especially after the build-up.”

Peterson was able to slay a bogeyman or two on Sunday. He quieted the scorching bat of Shohei Ohtani, a feat Mets pitchers were unable to do the previous two games, as the two-way superstar went 0-for-3 with a strikeout against Peterson. The lefty was also able to navigate a rare third trip through the lineup. Coming in, opposing hitters were slashing .314/.364/.588 in their third plate appearance against him.

After the Angels loaded the bases with one out in the seventh inning, Peterson was able to tiptoe out of trouble with as little damage as possible. He limited Chad Wallach to an RBI groundout and forced Andrew Velazquez to line out to preserve the 1-1 tie.

“I really liked the way Peterson finished the seventh inning, because things could have gotten away from him,” said Showalter. “You knew they were going to bring the left-handers off the bench there, and he’s not peeking in the dugout looking for any help.”

“After the first time, second time through, you look at that third time through -- guys have seen you now,” said Peterson. “So I was just trying to make sure I was on top of what I had done earlier. Really trying to get those guys off-balance that third time through.”

The Mets weathered a Luis Rengifo leadoff homer in the eighth inning, storming back thanks to their two stars. Francisco Lindor singled in the bottom half of the frame, then advanced on a wild pitch.

Pete Alonso, who returned to the lineup after exiting Saturday night’s game following a hit-by-pitch on the neck, delivered the game-tying RBI double with two outs.

Showalter spoke at length about Alonso’s resiliency and competitive fire, which he believes manifested in his willingness to step into the box again.

“I wish I could share some private conversations on it, it’d probably tell you something you already knew about Pete -- he didn’t walk away from it,” said Showalter. “He wanted to take it on. … I can’t tell you, in the context of safety, how much that means to an organization, team and young players.”

The heroics in the end came from Rafael Ortega, who laced a line-drive single that snuck under right fielder Hunter Renfroe’s glove, delivering the second walk-off hit of his career.

“I know that guy [Renfroe] has a really good arm,” Ortega said. “He always had a really good chance to throw it to home plate. Thank God he didn’t get that one.”