"We went in at half-time 1-0 up and probably disappointed with that," Black Cats boss Keane said after the game at The Stadium Of Light.
"They got the big boost with the equaliser and, with ten or 15 minutes to go, they were hitting us on the break a little bit and we were not really testing their goalkeeper.
"It seemed destined for a draw which, of course, we would have taken. But a striker's tackle and we end up losing the game.
"The players deserved better than that, but there you go.
"It is obviously very disappointing to concede in the last few minutes. We certainly deserved more than we got out of the game, particularly in the first half.
"It's a hard one to take, but that's football."