Bryce Harper has played his whole professional career in a Nationals uniform. He is the biggest star the Washington Nationals have had since they became the Washington Nationals. Harper, who may soon wear another team’s jersey, is also not having a good year.

But on Monday night, Harper’s .214 batting average—a disaster of a season, by most baseball standards—didn’t matter as he slugged his way to winning the annual Home Run Derby in a dramatic walk-off in front of an adoring home-field crowd.

Since 2013, when he finished second in that year’s Derby at Citi Field, Harper has been publicly reluctant to do it again. Swinging a bat over and over is tougher and harder on the body than it looks, and Harper insisted he would only ever get in another home-run contest if it happened at home.

When it does on this hot summer night in D.C., he and his teammates are into it: most of the other seven players get at least mild applause—save Atlanta first baseman and perennial Nats killer Freddie Freeman, who receives loud boos. (It’ll be the first of several times Freeman gets roasted, including during the waning seconds of his turn, when the stadium emcee asks if the crowd can “make some noise” for the Braves hitter, only to be told “NOOOO!”)

Harper’s announced last, and the fans lose it when he enters, wearing his home uniform paired with a D.C. flag headband instead of a cap. Max Scherzer, who’ll start Tuesday’s All-Star Game for the National League, finds a microphone and leads the crowd in a “Let’s go, Bryce!” chant.

Let’s get one thing out of the way: the Home Run Derby doesn’t matter, in any traditional sense of the game. This isn’t a game; everyone just wants to see some dingers. It’s silly by definition, a chance for players to goof around, and for fans to act like they’re back in Little League, even if it’s been half a century since it stopped being appropriate for them to bring a glove to the ballpark.

“Are you kidding? That’s was the first thing I fucking packed!” says 63-year-old Wayne Wright, who drove in for the All-Star Game festivities from Egg Harbor, New Jersey. Wright and his friend, Jack Stretch, are standing just behind Section 238 at Nationals Park, two levels above right-center field, where Los Angeles Dodgers first baseman Max Muncy has just deposited several of the dozen home runs he hit in the Derby’s second round.

Harper’s due up again, and people on the busy concourse press as close to home-run territory as they can. Eighteen-year-old Michael Sharp and his younger brother, Dylan, who drove up from Lexington, Kentucky, hang a few feet back and indulge in Harper nostalgia. Sharp takes out a phone and pulls up a photo of himself at age 10, with Harper, who was then in his single-A season with Hagerstown on a road trip through Kentucky.

“That was before he was a man,” says Sharp. “I think he’s going to be one of the greatest of all time.”

And what of the .214 average and 102 strikeouts at the midseason break?

“He’s my baseball crush. He’ll turn it up,” Sharp responds.

Harper comes up again and swats another 13 home runs to get to the Derby’s final round. Fireworks go off. Now Harper’s got to win this, otherwise the Home Run Derby will become one more time the Nationals got tantalizingly close to winning, only to let it fritter away.

During the long break between rounds, the talk turns to whether Harper, who’ll finally be an unrestricted free agent after this season, will stick around Washington. Sharp says yes, but maybe only for two years; Dylan thinks Harper will stay longer, since “he likes being the big man” and might not be the star attraction if he goes anywhere else.

By the time you read this, Harper’s winning final round will have been ‘grammed, tweeted, and dissected on SportsCenter for hours. You know the story already: the Chicago Cubs’ Kyle Schwarber clubs 18 balls out of the yard. Harper comes back, and if the evening wasn’t conspicous enough, the public-address system starts blasting “Don’t Stop Believin’.” One minute and 42 seconds in to his final turn, Harper’s only hit four. His dad, Ron, is throwing garbage. Another minute passes, and Harper’s stuck at nine. He takes his second time out with less than 90 seconds to go.

Finally, it’s time for the laser show: Nine of Harper’s final 10 swings send balls soaring into the seats and kids scrambling and diving to grab a souvenir, the last one tying Schwarber as the time runs out. But Harper’s qualified for bonus time, and needs only his first crack to win.

“I called it that he’d hit one over here,” says Accokeek resident Lamar Hyson, pointing to a Budweiser cart near center field where one of Harper’s final shots landed. “A guy had it in his hand but lost it.”

Down on the field Harper and his teammates are exulting what is perhaps his most statistically insignificant achievement of a career already full of accolades. This does nothing to change the Nationals’ disappointing record or raft of injured players. But it does etch a moment into the D.C. sports all-time highlight reel. And that matters.

Photo by dmbosstone on Flickr, used under the Creative Commons BY-SA 2.0 license.