And he crushed it.
The Nationals trailed the Cubs 3-1 in the top of the eighth inning before Harper came up to bat. He stepped in to face Cubs righty Carl Edwards Jr. Harper worked the count to 3-1 against Edwards until he got the green light of all green lights.
Edwards' fifth offering in the at-bat was an 80.4 mph curveball. Harper took a huge hack, sending the ball 421 feet to right field. The hit left Harper's bat at 108.9 mph, according to ESPN's Home Run Tracker. That was the hardest hit home run of the day for any MLB team.
Harper did a simple bat-flip after tying the game at 3-3. Ryan Zimmerman followed in the inning with a go-ahead 3-run shot for the Nationals.
The Nationals went on to win the game 6-3 to tie the series at 1-1 heading into Game 3. Harper went 1-for-4 with a run scored and two RBI in the win.
"I try to stay as calm as I can throughout the whole game," Harper said after the game, according to MLB.com. "I think that's what makes our team so good. Nobody knows if we're frustrated or happy or sad or anything like that. I think we are a very even-keeled team."
First pitch for Game 3 of the National League Division Series matchup is at 4:08 p.m. Monday at Wrigley Field in Chicago.
"Why not? Swing as hard as you can," Harper said, according to the Washington Post. "Pretty good moment."