Things got ugly in Washington, D.C., Sunday afternoon when two Nationals players fought in the dugout.

Relief pitcher Jonathan Papelbon attacked the team's star hitter, Bryce Harper, grabbing him by the throat in the dugout. 

It all started when Harper flew out in the eighth inning. As he came back to the dugout, Papelbon appeared to take issue with Harper's lack of hustle in running to first base.

As the two exchanged words, Papelbon lunged at Harper, grabbing him near the throat and pushing him back into the wall. 

Teammates quickly intervened before any punches were thrown. 

Harper said after the game that Papelbon had apologized.

"I mean, he apologized, so, whatever. I really don't care," said the 22-year-old, who leads the league in batting average, home runs, slugging percentage, and on-base percentage.

Papelbon, who is in his 11th season, said he was "wrong" after the game, adding that he should not have allowed it to happen in the middle of a game.

The brawl came one day after the Mets clinched the NL East title, eliminating the disappointing Nationals from playoff contention. 

Manager Matt Williams blamed the scuffle on "testosterone flowing among young men." 

Papelbon was suspended by the team Monday for four games without pay. He will also drop his appeal of a three-game suspension by MLB for a separate incident, meaning he will not pitch again this season.

Read more from AP:

Papelbon (4-3), who entered in the eighth, went back to the mound for the ninth in what was a 4-all game. He allowed five runs, including Andres Blanco's go-ahead, two-run homer.

Why did Williams keep Papelbon in the game after the scrap?

"He's our closer," Williams said. "That's all I'm going to say on the matter. He's our closer. In a tie game, he's in the ballgame in the ninth inning."

After Blanco's homer, Papelbon loaded the bases, hitting Odubel Herrera with his final pitch before being removed by Williams — and leaving the mound to a chorus of boos from the Nationals Park crowd of 28,661.

"Sometimes, emotions spill over and that's what happened today," Papelbon said. "It's happened for hundreds of years in this game and I think it will continue to happen."

Watch the fight below.

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