In the end, it was Harper who tossed his cap -- literally -- as he approached home plate, his teammates waiting to mob him after his third career walk-off home run.
Harper's 11th home run of the season, which gave him the National League lead, secured the Nats' 8-6 win over the Braves, sending Atlanta to its seventh loss in 11 games. Washington has won nine of 11.
"He's the hottest player in the world right now," said Atlanta reliever Cody Martin, who surrendered the game-winning home run with one out and a runner at first in the bottom of the ninth inning.
"He's putting good swings on everything, he's seeing the ball well, his balance is good. You can't really do any one thing to him that's going to get him out. I think you just have to keep mixing it up, and that just wasn't the right pitch there."
Martin threw Harper a 1-0 slider, which the 22-year-old golfed to deep right-center field.
"It really wasn't terrible," Martin said moments after watching replays of the home run from the Braves' clubhouse.
"He put a good swing on it. ... We're trying to go away and it came back middle, but it was kind of shin-high and he went down and put a good swing on it. So credit to him."
Harper went 2-for-4 with a walk and has now reached base in 23 of his last 24 games. For the second straight night, Braves manager Fredi Gonzalez was left wondering how to cool down the game's hottest hitter.
"When a guy is going that good, that hot," Gonzalez said, "you almost have to bounce it in there, and maybe even then, he can maybe hit it out of the ballpark."
Harper became the first player to hit six home runs in three games since Hee-Seop Choi did it with the Los Angeles Dodgers from June 10-12, 2005.
"There's not much you can do against someone that is that hot right now," Bethancourt conceded. "You just have to wait until he cools down, and hopefully that moment will come."
Harper's game-winning blast spoiled what had the makings for a tremendous Braves comeback.
Atlanta trailed 6-1 in the seventh inning, but rallied to tie the game in the eighth, with a two-out, two-run double from Bethancourt pulling the Braves even.
"I'm really proud of our club -- that our starter [Julio Teheran] goes out and gives up six runs and we came back and we didn't fold," Gonzalez said.
"Our bullpen gave us a chance to win, and even though we didn't, I'm really proud of the way we battled back. There's no column for that -- you either get the 'W' or the 'L,' but I'll tell you what, I'm proud of those guys today."