The Washington Nationals superstar player Bryce Harper charged the mound after San Francisco Giants pitcher Hunter Strickland nailed Harper in the hip with a 98mph fastball.
Harper points out to Strickland with his bat immediately following the pitch and give him a few choice words, then takes off his helmet and runs out to the mound. Both teams' benches clear as Harper and Strickland exchange punches and go to the ground.
Both players got ejected from the game. Many view the pitch as being intentional. The at-bat was the first time the two faced each other since the 2014 playoffs, when Harper launched two huge home runs off Strickland.
The Nationals won the game 3-0.