Patrick Corbin suffered his second consecutive subpar outing, allowing five runs — three earned — on five hits and five walks in five innings to fall to 5-4 on the season. (Denis Poroy/Getty Images)

— The Washington Nationals bottled all of their offense into one inning, into their first six hitters, into a quick rally that brought a jolt of energy that would only fade as a misty Thursday night rolled along.

After that early burst, once their bats calmed, then cooled, then froze altogether, the Nationals were left with a 5-4 loss to the San Diego Padres at Petco Park. They scored four first-inning runs for starter Patrick Corbin. He couldn’t hold that advantage, giving up five runs — just three of them earned — in five shaky frames. The Nationals’ heaving bullpen kept them close, and gave them a final breath to work with, but five Padres pitchers retired the last 20 batters Washington sent to the plate.

Starter Joey Lucchesi teamed with relievers Matt Wisler, Trey Wingenter, Craig Stammen and Kirby Yates to keep the Nationals off the base paths for the final six innings. Washington’s last threat, if it could be described as such, was a third-inning double from Brian Dozier that led nowhere. Instead, the Nationals dropped another series opener and ended a four-game winning streak. They are 28-34, and seven back in the National League East, because their offense couldn’t continue its recent surge through another game.

It was averaging close to seven runs a contest in the 9-2 stretch that led into Thursday. Then it flatlined.

“It was just one of those days,” said Manager Dave Martinez. “We came out, swung the bat well in the first two innings. And then they shut us down.”

Corbin’s struggles really began last Friday, in a lopsided loss in Cincinnati, when the Reds scored eight run against him — six of them earned — in 2⅔ innings. Now the Padres, like the Reds, were patient as his fastball flew all over the zone. And, like the Reds, they laid off his biting slider to force him into long counts. And, like the Reds, most importantly, they used a home run and a crooked inning to capitalize on Corbin’s command issues and chase him from the game.

He had been handed that four-run lead before stepping on the mound, after the Nationals leaped ahead on Howie Kendrick’s two-run single and Brian Dozier’s two-run home run off Lucchesi. But that dissipated over the course of five innings, starting with Hunter Renfroe’s two-run blast in the bottom of the second. That only came after Corbin issued a leadoff walk to Franmil Reyes, and he loaded the bases before escaping with a lazy pop up. Then he settled into a bit of a groove, retiring seven straight, until the fifth inning rolled around.

“I just felt a little off, felt a little quick front-side,” Corbin said of his mechanics. “I thought after that, made a couple adjustments and felt better, thought I was in the zone a little more, but I was just falling behind today, pretty much throughout.”

It’s hard for a pitcher to avoid big rallies when he can’t locate his fastball, or utilize his out pitch, or receive sound defense when he does get a favorable swing. All of that was working against Corbin on Thursday as the Padres pestered him and his pitch count skyrocketed toward triple digits. Manuel Margot led off the fifth with a single, Fernando Tatis Jr. smacked one, too, and Corbin then walked Wil Myers to load the bases. Except this time he couldn’t navigate out of the jam before damage mounted.

Machado bounced a grounder to Trea Turner and he tried a short toss to third for a force out. But Anthony Rendon couldn’t handle the high throw and, as a result, two runs scored to tie the game. Reyes, the next batter, nudged the Padres ahead with a sacrifice fly. Corbin soon exited at 101 pitches, only 57 of them strikes, and with a season-high five walks on his line.

He blamed himself for issuing too many free passes and not having his best stuff. But Turner, when asked about that sloppy play in the fifth, pointed the loss in his own direction.

“I was just trying to be too perfect,” Corbin said. “Instead of attacking their hitters with everything I have.”

“Looking back at it, if I make a better throw we get out of that inning with a lead and probably win the game,” Turner said about 10 minutes earlier in a quiet clubhouse. “Kind of was the difference.”

Together they forced Martinez to confront the question that has nagged him since Wednesday afternoon: Who was going to come out of the Nationals’ bullpen? They came to San Diego having taken back-to-back games from the Chicago White Sox, good for their fourth series win in a row, but their relievers were depleted in the process. Closer Sean Doolittle pitched in each victory. So did Tanner Rainey and Wander Suero, and Kyle Barraclough threw 24 pitches in the second game. That left Matt Grace, Tony Sipp, Javy Guerra and Kyle McGowin as Martinez’s rested options. And that felt like trouble.

Yet they that patchwork group was able to hold the game together. Sipp was the first to emerge, taking the ball in the sixth with the Nationals trailing by a run. He got two outs before he gave up a single and was lifted for Guerra. He got the final out of that inning, worked through the seventh unscathed, and got the first out of the eighth before he was lifted for Grace. He induced a double play to give the Nationals their last chance in the ninth, when one swing could have knotted the score and jolted the offense awake once again.

But that swing never came.