The Trotters are still four points adrift of fourth from bottom Birmingham but their goal difference has widened after two-goal Gareth Barry helped Villa claim their first win in four games.
Boss Gary Megson's side have now taken only one point from their last eight games and face what he described as a must-win game with West Ham next Saturday.
Megson said: "We didn't do enough today to get a result. We got off to a poor start, giving away a goal inside in the first 10 minutes, and it was difficult after that point.
"We had our best period just after half time but the second goal left us facing an uphill battle and then we conceded some sloppy goals.
"People ask whether we have been affected by the defeat against Arsenal after leading 2-0 against 10 men but we can't blame that for today.
"The fact is we are on an awful run with just one point from the last eight games which has seen us slip into this position.
"But I don't think anyone is giving up and I would be disappointed if that was the case.
"The only positive about today is that the places at the bottom haven't changed although our goal difference has taken a hit.
"We can close the gap but now we have a huge home game against West Ham. People go on about must-win games and that is as near as you can get to that.
"We can't do a massive amount about other people's results but we have to get one ourselves very quickly.
"If we put in a good performance the belief will soon come back and the focus in on these last five games."