Two baseballs turned the Washington Nationals’ taut, tie game into a delirious, raucous victory Saturday night. They lived short, painful lives. Danny Espinosa destroyed the first one, a slider that zipped out over the visitors’ bullpen at Nationals Park as if blasted out of a cannon. Bryce Harper obliterated the second, a curveball that peeked at the third deck hanging above right field, nosebleeds typically only visited by fans unafraid of heights. And birds.

The two vicious swings, taken in the eighth inning by a pair of sluggers in slumps, turned a complex, messy game into a party from the dugout to the last row. So much led to the Nationals’ 10-7 victory over the Miami Marlins: three unearned runs on three errors; a five-inning start from Jordan Zimmermann; two home runs by Adam LaRoche; a dramatic, station-to-station rally in the eighth. And then Espinosa and Harper blew the lid off everything.

“This is how it’s supposed to be,” Espinosa said. “When you’re in first place, you should be playing in front of a sold-out crowd. It should be loud. It should be a great atmosphere. This is what you dream of as a kid to play in front of.”

A night that began with sloppy play delivered the type of baseball thrills Washington has waited generations for. The victory nudged the Nationals’ lead in the National League East to three games as the Atlanta Braves lost. Players in the dugout embraced in group hugs. Espinosa took a curtain call. LaRoche hugged his 9-year-old son, Drake. The fever of a pennant race, perhaps like never before, enveloped Nationals Park.

Five tenured Nationals players said the crowd, 33,449 strong, grew louder in the eighth inning than they had ever heard it, with the possible exception of Stephen Strasburg’s debut in 2010. “People stayed, too,” said Ryan Zimmerman, who’s seen more games here than anyone. “In the past, they would have left.”

“Awesome,” said catcher Kurt Suzuki, who made his Nationals debut. “That was awesome.”

The Nationals’ rollicking rally from a 6-4 deficit made the night crackle. It built slowly at first. LaRoche rolled a groundball to first base, but he reached when reliever Mike Dunn, covering first, dropped the ball. Jayson Werth followed with a walk. Then Suzuki chased two high fastballs and struck out.

The park deflated, then perked up as Steve Lombardozzi walked to the plate. Earlier, his booting of a groundball led to the Marlins’ sixth run, and their third unearned run of the game. Now, he ripped a single back up the middle.

LaRoche lumbered around third as center fielder Gorkys Hernandez’s throw sailed in from center. He ignored Tyler Moore’s suggestion to slide and tried to step around catcher John Buck’s foot. Even super-slow-motion replays could not conclusively show whether LaRoche’s toe clipped the plate, but he was called safe and the Nats had cut the lead to one.

“I didn’t know if I did,” LaRoche said. “Yeah, there was a little miscommunication there. I should’ve slid. But it worked out.”

With the trying run on second, Moore ripped a 1-2 fastball into right field. Werth slid home. The game was tied at 6. The roar built and built.

“It was crazy, man,” Moore said. “That crowd got pretty loud at the end there.”

Espinosa strode into the batter’s box with the Nationals in need of a hero, a predicament he bore responsibility for. His two throwing errors had led to two unearned runs against Zimmermann, whose streak of 21 straight starts of at least six innings was snapped because of them.

“I made two stupid errors, and I’m not trying to think about those when I’m coming up to bat,” Espinosa said. “I’m trying to let those stay behind me and move on and separate my defense from my offense.”

He had also been mired in a 4-for-41 slump. He is not a player who takes struggles easily — he grips the bat tighter and grits his teeth. Manager Davey Johnson implores him often to relax.

“Young players with a lot of ability try to expand, try to make something happen,” Johnson said. “And sometimes they’re their own worst enemy.”

With the count 2-2, Dunn threw him a slider. Espinosa annihilated it. The crowd exploded upon contact. Espinosa threw down his bat and ran around the bases. Werth pushed him out of the dugout for a curtain call, and Espinosa hopped up the steps and lifted his hand.

“It’s a great feeling, to just be able to come through,” Espinosa said. “I’ve had a lot of situations this year where I think I haven’t done so well, and to be able to come through for the team like that felt really good.”

Harper came to the plate, like Espinosa, trying to break out of a rough patch. His batting average for the second half hung below .200. Hitting coach Rick Eckstein had told him not too put so much pressure on himself. Johnson asked him, “Is it possible you could relax?” Harper responded, “I can’t change.”

Dunn tried to throw him a 2-2 curveball, and Harper crushed it. Drew Storen said that from his seat in the Nationals’ bullpen, “It looked a 3 wood.” The ball soared over his head. Harper admired it for a moment and then tossed his bat maybe seven yards. The place erupted again.

“I knew I barreled it up,” Harper said, starting to smile. “It felt good off the bat. I was just hoping I could run around the bases so finally I could touch first base again.”

The game’s end made you forget what a nail-biter it had been. They entered the eighth trailing by two runs. Then the game turned dramatic. And then it turned into a celebration, a hard-to-forget night, one of the most fun innings of a remarkable season.

“You could say that,” LaRoche said. “It started out a very sloppy game on our end, really for the majority of that game. To turn it around like that just says something about this club. Not that we should be surprised. We’ve been doing that all year.”