Cincinnati Bengals safety Shawn Williams was ejected for a helmet hit on Indianapolis Colts quarterback Andrew Luck on Sunday under the National Football League's new "use of helmet" rule.
Williams lowered his head and made helmet-to-helmet contact with Luck, who was being taken to the ground in a tackle from behind by another player during the first quarter.
Under the new rule, designed in the hope of minimising head and minimizing injuries, officials have the discretion to eject a player for such a hit.
The rule states that a foul occurs if a "player lowers his head to initiate and make contact with his helmet against an opponent anywhere on his body."
Luck did not appear to be injured in the collision.