Haula skated hard into the Dallas crease and collided with Lehtonen, knocking the veteran goalie's mask off and drawing blood.
Lehtonen left the ice after he was tended to by the Stars medical staff. Tim Thomas, who was acquired in a trade Wednesday at the NHL Trade Deadline with the Florida Panthers for goalie Dan Ellis, entered the game for Lehtonen, making his Dallas debut.
Haula, who scored in the first period, was assessed a charging major and a game misconduct.
Lehtonen stopped 26 of 29 shots he faced. The Wild held a 3-2 lead when he exited the game.