With the scores at 0-0 and both teams looking for the crucial goal, David Luiz was given his marching orders after 87 minutes by referee Michael Oliver.
The Chelsea defender was tussling with Alexis Sanchez but he lost control of the ball and lunged towards Sead Kolasinac.
His studs were raised and he went over the ball and made contact with Kolasinac's ankle. It looked like a nasty one.
Luiz had already been booked but was given a straight red for the dangerous tackle.
Check out the challenge below.
David Luiz with an ankle breaking tackle on Kolasinac "The Tank". #CHEARS pic.twitter.com/gj0kCoz1zk
— Oscar (@oscarkinoti) September 17, 2017