Wagner took a charge from Antetokounmpo, who didn’t like the call in what had become a physical game.
During a break in the action with Milwaukee challenging the call, Antetokounmpo approached Wagner and started jabbering at him before headbutting him and drawing the ejection in the second quarter.
He had 12 points and nine rebounds in 10 minutes before exiting the floor.
The game itself is meaningless.
The Bucks have already clinched the top seed in the East, while the Wizards, who are winless in the bubble, have already been eliminated from playoff contention.
Antetokounmpo’s headbutt could draw a punishment from the league and keep him out of the team’s final seeding game against the Grizzlies on Thursday.