Patrick Corbin allowed four runs in five innings against the Mets. (Elsa/Getty Images)

It was quiet Monday night at Citi Field, a light crowd still easing into the week, and the Washington Nationals so nearly gave it a reason to erupt in shouts and boos.

But those will have to wait for another game, maybe as soon as Tuesday’s, because the New York Mets held off a Nationals comeback in a 5-3 win. It was the second straight night that the Nationals were buried by a bad start, spun their wheels into a late push and, in the end, could only get close against an opponent’s bullpen.

Patrick Corbin was the improbable culprit in this one, giving up four early runs as his teammates tried to bully Mets starter Wilmer Font. They couldn’t, at least not enough across his four frames, and the gap widened back to two when Tony Sipp gave up an RBI single to Dominic Smith in the eighth. The loss dropped the Nationals to 2-14 in series openers and yet another game below .500 at 19-28.

“There’s no reason. We just have to come ready to play right out of the gate and take Game 1,” right fielder Adam Eaton said. “And we haven’t done that. We haven’t really played well in any instances. Have we been any better in Game 2 with the percentages? We just haven’t played well.”

The Nationals entered Monday staring down a critical stretch of 10 division games in 10 days. The first four would come against the Mets, here in Queens, with New York’s manager on a burning seat and its losing streak at five heading into the series. Then four against the Miami Marlins, the owners of baseball’s worst record despite sweeping the Mets over the weekend, the perfect way for Washington to flush the lingering issues that have shoved it into fourth place in the National League East. Then, to finish, the Nationals’ first two meetings with the Atlanta Braves.

And it all began with the exact matchup the Nationals dominated less than a week ago in Washington. Corbin, one of their three aces, carved through the Mets’ order that night and gave up one run in eight innings. Font, a fringe major leaguer, couldn’t hold the Nationals down. But baseball games aren’t played on paper for a reason. If they were and results were based on probability, no one would have had to show up at Citi Field. Some energy could have been saved. Some time could have been spared.

“You come into the game, and you got Corbin out there,” Manager Dave Martinez said, “and you think, starting the game, you got a really good chance of winning.”

Then Corbin threw a fastball right down the middle to Amed Rosario with one out in the first, and everything flipped. Rosario’s home run was followed by Pete Alonso knocking a low-and-in sinker over the left field wall two batters later. Corbin has given up eight homers this year, and, oddly enough, five have been hit by the Mets. He yielded 15 all of last season, during a solid year with the Arizona Diamondbacks, and loud mistakes, however scattered, have been the downside of his strong start to this year.

The Mets tacked on two more runs in the third as Corbin’s command sagged. He walked Rosario to start the inning, extended it by walking Wilson Ramos with two outs and then let Rosario score on a Todd Frazier single. Next Ramos came home on a Carlos Gomez double to make it 4-0. Corbin didn’t have the stuff that has propelled him in recent outings — not his disappearing slider or his plus sinker — but he did retire the last seven batters he faced.

“They’ve seen me a lot, I’ve seen them a lot, and tonight they got me,” Corbin said. “I just made a couple mistakes, wasn’t as sharp as I’ve been, so just try to move on.”

He still gave the Nationals another puncher’s chance to get back into the win column. On Sunday, in a series finale with the Chicago Cubs, Washington was buried in a four-run hole and wound up losing, 6-5. That comeback was keyed by a three-run home run from Anthony Rendon. This time, with Corbin turning in five innings of spotty work, the surge began with a Rendon homer off Font in the fourth before Yan Gomes cut the deficit to 4-2 with an RBI single later in the inning.

But now came the hard part, what the Nationals couldn’t do against the Cubs, pushing past a moral victory and working all the way back. The eighth produced one run, inching them closer, but nothing more. The ninth brought a rally hollowed out by bad situational hitting. Washington has lost in a lot of ways this year, with its bullpen imploding or its offense slumping or its errors piling up. But rough nights for Corbin, Max Scherzer or Stephen Strasburg have been rare and, beyond that, something this team cannot afford.

And beyond even that, once Corbin was out and the game tightened, the Nationals were again burned by a defensive mistake when reliever Joe Ross threw away a pickoff throw in the eighth. That put Gomez in scoring position, and he soon trotted home on Smith’s single off Sipp. It was an insurance run the Mets would lean on once the Nationals put the tying runs on base with nobody out in the ninth.

Washington then had to play for two instead of one, a significant difference because of Ross’s miscue, and wound up with nothing at all.