Sunderland 1 Manchester United 1
The former Irish skipper had been clashing on and off with former international colleague Jason McAteer all game and with just seconds remaining he connected with an elbow on the Sunderland player.
Referee Uriah Rennie was left with little alternative but to show Keane the red card and he must now contemplate a lengthy ban for a disgraceful action.
The game itself was a lively one, but United will be wondering how they did not win.
They took the lead after just seven minutes when Ryan Giggs punished a slack clearance from Claudio Reyna to score.
Keane had picked up the ball from the American and threaded the Welshman through before beating Thomas Sorenson.
The Black Cats, though, held their ground and despite United's domination, they could not convert a second chance and debutant Tore Andre Flo punished them.
Flo, who scored on his debut for previous clubs Chelsea and Rangers, kept up his record with a goal 20 minutes from time.
McAteer had the original effort after being put through by Thomas Butler, but Roy Carroll's save dropped to Flo who smashed the ball home.
Sorensen produced two magical saves late on to deny Ruud van Nistelrooy and Keane, but the home side's late efforts were enough for them to earn a draw.
