The quarterback scrambled on a third-and-7 play. As Luck dove for the first down, while being tackled, Williams flew in and struck the QB in the helmet.
Luck, who missed all last season, popped back up and remained in the game.
Flags immediately flew for the personal foul penalty. After discussion, and possible input from the NFL's officiating command center in New York, Williams was ejected.
The brutal hit is the type of strike the league is trying to get rid of in football.