Special delivery, courtesy of Adam LaRoche, whose 11th-inning home run against Arizona clinches the Nationals’ third straight walk-off win. (Patrick Smith/Getty Images)

It was the top of the 11th inning when Craig Stammen loaded the bases with no one out. The Nationals’ magical win streak looked doomed. In a weekend of walk-off wins, they’d survived mistakes with clutch hits, overcome missed opportunities with quick comebacks and persevered through extra innings with adrenaline. The Nationals had done all three by the 11th of Monday’s game.

But Stammen struck out one Arizona Diamondback, then another. Then a weak groundball to second base. Unbelievably in the context of the evening, but inevitably in the context of a magical week, Stammen escaped.

In the bottom of the inning, the Nationals wrote their latest chapter of August magic. For the second straight day, it arrived in the 11th. For the third straight day, it came on a walk-off hit. This time, it was Adam LaRoche, who wasn’t looking for the 3-1 curveball he got from Will Harris, but crushed it all the same. His first career walk-off homer gave Washington a 5-4 win, its seventh straight.

“I got every bit of that one,” LaRoche said. “Just a crazy few days. I don’t know how we’ve gotten into these walk-off situations the last few days, but we’ve been able to grind back.”

Stammen and LaRoche joined a list that included Wilson Ramos on Saturday and Asdrubal Cabrera and Scott Hairston on Sunday, beneficiaries of whatever force has pushed the Nationals into their longest winning streak of the season, the heroes of the day in a run that’s seen many of them.

The Post Sports Live crew debates what the odds are that the division-leading Baltimore Orioles and Washington Nationals meet in the World Series. (Post Sports Live/The Washington Post)

“It just feels like every break is going our way,” Stammen said. “You don’t get out of a bases loaded jam very often. That’s a once-in-25-time thing. Walk-off home runs with two outs in the 11th. Coming back when we were down, all that stuff. Giving up home runs, coming back and scoring more runs, it’s just resiliency.”

Head-shaking base running, failed bunts, and a leadoff walk turned into a run gave a half-full Nationals Park the impression that Monday night might mark the end of the magical run. Jordan Zimmermann walked three men for the first time all year, and two of them came around to score.

“That’s why we preach ‘don’t walk anyone,’ ” Zimmermann said. “Two of my walks scored. We could’ve been home a lot earlier.”

Tyler Clippard allowed a run for the first time since July 12. Denard Span and Bryce Harper both ran into outs, and Zimmermann failed to advance a runner on a bunt.

Still, Washington found itself down only one in the seventh, when Ian Desmond walked and Ramos sent a low line drive over the 402 sign in dead center for a 2-1 lead.

The late-inning magic was revived; the Nationals appeared to have found a way again.

But then Didi Gregorius, who’d stifled Washington rallies with tremendous plays at shortstop, in the hole and charging in and all over, smacked a two-run homer of his own in the eighth. He’d confused the momentum, though only momentarily.

Anthony Rendon tripled home Span in the bottom of the inning, a line drive that touched down just inside the right field line. Jayson Werth then scored him with a sacrifice fly.

Clippard came in with a 4-3 lead in the ninth, as struggling closer Rafael Soriano got the night off. He’d been nearly untouchable for about a month, allowing just four hits in his previous 14 outings. And then he surrendered a tying home run to David Peralta. Then Stammen got into and out of trouble. Two blown saves in two nights for the Nationals, and two wins.

“It doesn’t help your bullpen, for sure,” Manager Matt Williams said of playing extra-inning games. “We want to make sure we’re mindful of everybody’s health and their load, but we get in a situation where we can win a game, we’ve got to try and do that, too.”

The fatigue of a week’s worth of late-inning excitement showed in Clippard’s uncharacteristic fraying. The power of a baseball team on an unrelenting hot streak patched it up.

“It’s nothing a pitcher ever wants to get into,” LaRoche said of Stammen’s 11th-inning escape. “But for him to grind back right there, that could’ve easily been a disastrous inning with the bases loaded and nobody out. To fight back and make those pitches to get us back into the dugout, it was big for us.”

By the time LaRoche whacked the ball off the facade in right field, that immeasurable baseball force — fate, momentum, luck, whatever — was back in the Nationals dugout. Stammen was a winner, LaRoche was a hero, and the Nationals had done it again.