The Nationals are finally improving on their below .500 start to the season. Post Sports Live debates whether the team is playing up to its potential. (Post Sports Live/The Washington Post)

Bryce Harper knew as soon as he hit it, giving him plenty of time to stand and watch as his walk-off home run soared into the right-center field stands. Yunel Escobar knew a split second later, watching about halfway between first and second, in plenty of time to throw his right fist in the air as he rounded the bases. Washington’s dugout knew right away, in plenty of time for the Nationals to surround home plate as Escobar and Harper crossed it, the final runs of an 8-6 win that pushed the home team above .500 for the first time this season.

Perhaps everyone in a sellout Nationals Park crowd Saturday should have known as soon as Harper came up in a tie game with one out in the ninth that it would end this way. Given that the 22-year-old had homered five times in his previous two games, perhaps him not homering would be more unbelievable than him hitting a hanging curveball into the seats. He is on such a tear that his 2-for-4 day qualifies as his least impressive performance in the past four games.

“Awe,” said Nationals shortstop Ian Desmond, asked to describe the feeling he gets when watching Harper these days. “It’s just so fun to watch.”

Over the past three games, Harper has gone 8 for 12 with six home runs and 12 RBI – 50 percent of the Nationals’ total offensive output in that span. It appeared the Nationals might not need his production Saturday as they carried a five-run lead to the seventh and a three-run lead to the eighth. Then their bullpen required it.

Starter Doug Fister left with a three-run lead in the seventh, but Aaron Barrett let three of four batters reach to begin the eighth. Braves catcher Christian Bethancourt hit a two-run double off Tanner Roark to tie the game.

Check out the new Nationals' pitcher Max Scherzer, who recently joined the team from the American League, swing a bat during his first week of hitting practice at spring training. The Nats gave him a seven-year, $210 million contract, but can he successfully lay down a bunt? (McKenna Ewen/The Washington Post)

The Nationals nearly went ahead in the bottom of the eighth. Jose Lobaton — who had three hits, including a two-run home run — singled to lead off the inning. Michael A. Taylor pinch ran and stole second base. The Nationals have stolen four bases this year, and Taylor has three of them. Then Dan Uggla delivered a pinch-hit single to left, but Atlanta’s Kelly Johnson threw out Taylor at the plate. The score remained tied, setting up Harper for the drama in the ninth.

“He’s obviously playing very well right now,” said Nationals first baseman Ryan Zimmerman, who hit a three-run home run in the fifth. “We’ve all kind of seen his talent, and it’s nice for him to put it together for a whole week here. Really this whole season he’s been great. The great thing is he’s still learning and he’s gonna continue to get better.”

Harper is getting better in right field, too. He made seven putouts there Saturday, including a catch made in a flustered pursuit of a line drive by Nick Markakis that saved a run.

“He’s doing everything well right now,” Nationals Manager Matt Williams said. “Playing great defense. He made a great play today on Markakis, a couple of great sliding plays and of course the game-winner.”

Harper said this is why the Nationals drafted him, that when he’s healthy, this is how he should be playing, “plain and simple.” But perhaps only a wardrobe malfunction can stop Harper now: Jayson Werth tried to rip off Harper’s jersey after the home run and tore off all the buttons.

“Hopefully they can fix that tonight so I can wear it tomorrow,” Harper said.

Lost in the late-inning pyrotechnics was another strong performance from Fister, who has not walked a batter in 18 innings. Fister pitched six strong innings before tiring in the seventh. While his sinker was not dipping as much as it sometimes does, many Braves hitters flew out or lined out, unable to make solid contact — exactly the type of swings Fister generates when he is at his best. Three Braves struck out looking at 87 mph sinkers. In the absence of velocity, movement creates deception.

Through four innings, Fister himself had more hits — one, a double to right-center — than the Braves. But the three runs charged to Barrett in the eighth meant Fister did not earn the win. Drew Storen got his first victory of the year, instead, thanks to the scoreless ninth.

“I was upstairs here finishing up treatment and getting things done [when Harper homered],” Fister said.” I can tell you that everyone who was in here, trainers and any staff that was in here, we were certainly screaming at the top of our lungs. It was quite a turnaround for us.”

Saturday’s homer clinched a fourth straight series win for Washington, and was the Nationals’ ninth win in their past 11 games. Twelve days ago, a day before Max Scherzer showered Uggla with chocolate sauce after his go-ahead home run in that memorable comeback in Atlanta, the Nationals were six games under .500, had lost six straight and sat in last place in the National League East. By the time Scherzer showered Harper with chocolate sauce Saturday, the Nationals were in second in the division and, at 16-15, a winning team for the first time all season.