WASHINGTON — Bryce Harper won the Home Run Derby in his home ballpark, providing another memory to Nationals fans in what could be his final season in Washington.

Harper gave an uppercut fist pump after matching Kyle Schwarber’s 18 homers in the championship round on the final swing of his allotted 4 minutes. Because he hit two homers over 440 feet, Harper got 30 seconds of extra time. He launched the winning blast on his second extra swing, holding his bat over his head and walking down the first-base line as it cleared the center-field fence.

The 2015 NL MVP has had an uneven season and the Nationals are stuck at .500 after making four playoff appearances in the previous six years.

The Chicago Cubs’ Schwarber hit the most home runs in the derby with 55 through three rounds. But Harper was the only player to get the crowd roaring.

Harper and Schwarber each advanced to the finals by ousting the Dodgers’ Max Muncy and the Phillies’ Rhys Hoskins.

The crowd favorite in his home stadium, Harper needed 13 homers to eliminate the Muncy, and he blasted his 13th to right field with about a minute left in his 4 minutes of hitting time.

Schwarber needed 21 homers to eliminate Hoskins, who had 20. Both players had 37 homers through the first two rounds of the competition.

Harper had the most homers over 440 feet through two rounds with nine.

This was Harper’s second Home Run Derby. He previously participated in 2013 and said he would give it another try when the All-Star Game came to Washington.

Wearing a District of Columbia flag bandanna on his forehead, Harper hit 13 homers in the first round to eliminate Freddie Freeman.

He hit six homers measured at more than 440 feet, the most of any competitor.

The son of former major league pitcher Bobby Witt won a competition for high-schoolers during the Home Run Derby.

Bobby Witt Jr. hit eight homers in 90 seconds to beat Rece Hinds by one.

Witt’s dad pitched for seven teams in 16 seasons, winning 142 games. He spent most of his career with the Texas Rangers and was never an All-Star.