The defeat served as a sobering reality check for Sunderland boss Paolo Di Canio.
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After defeat in his first match at Chelsea, the Italian has been riding high with a stunning derby success at Newcastle and a fine win over Everton.
Things changed at Villa Park, though, and Di Canio was apologetic and suggested his players thought survival was already secured.
"It was not a shock but a very bad defeat. Our performance, I am not very happy," he said.
"We thought the main job was done. It is obvious if the team perform in this way. The first responsibility is (with) the manager and then the players.
"This is a medicine that can let us understand that we have to play with desire and commitment, otherwise we have a defeat. It is obvious this is a humiliation that can help. It is not acceptable tonight."
Sunderland were backed by a large number of traveling fans and Di Canio added: "We have to apologise to our club, the fans, they travel and it is not fair.
"Every time we can lose, but not in this manner. Aston Villa, a team with real desire, played like (it was) the last chance of their lives. Maybe we were fooled by two wins in a row and now we have to make sure we get points against Stoke at home."
The Black Cats' night was topped off when Stephane Sessegnon was sent off for a challenge on Yacouba Sylla.
Di Canio plans to appeal the decision which, if not overturned, will rule the striker out for the rest of the season.
"We saw the clip, there is not a bad challenge," he said.
"With the dynamic of the challenge, it can be a trap for the referee because from distance you see the dynamic, but there is not a nasty challenge.
"We will appeal of course."