Their failure to capitalise properly on 45 minutes of compelling superiority over David O'Leary's team was penalised by the cultured boot of Nolberto Solano.
The Peruvian's curling free-kick just before half-time cancelled out a rare goal from the troubled head of Harry Kewell, leaving Rafael Benitez to reflect that Steven Gerrard, for all his qualities, lacks the striker's art. The Liverpool captain, whom Benitez has asked to be an attacking force with so few front players at his disposal, ran himself into the ground in support of lone striker Neil Mellor, but could not convert any of three good chances that came his way - chances from which a Djibril Cissé or a Milan Baros might have killed off the home side even before half-time.
In the second half, extraordinarily, Liverpool might have been another team as the incisiveness of the first half all but vanished. Villa did more to keep the ball, but little else different.
Benitez uttered no word of criticism of his team leader, nor should he have done, given the energy Gerrard expended as Villa teetered on the brink of collapse. The bottom line, however, is that Liverpool still have only one win away from home this season, their chances of threatening the Premiership leaders, or even reaching the top four, in danger of slipping beyond their scope. Progress to the knock-out stages of the Champions' League, in which they face Olympiakos next Wednesday, now looks crucial.
O'Leary made no attempt to conceal his surprise at the result. "We got out of jail big time," he said. "In the first half we were outclassed and I can't really explain why the second half was different. Maybe they couldn't believe they had come off at half time only 1-1." Against Gerrard, Didi Hamann and Xabi Alonso in a Liverpool side restored to senior strength after the youth-inspired League Cup triumph over Tottenham, Villa had been obliged to call up 20-year-old Steve Davis in place of the suspended Lee Hendrie.
O'Leary called it a mismatch, although Davis marked only his second full game with a performance of unfussy efficiency. It was in defence that Villa looked in need of reinforcement. But after Gerrard - repeatedly on the end of some irresistible moves - had fluffed one volley, fired another over the bar and then shot straight at Thomas Sorensen, Liverpool were left with only Kewell's 16th-minute header to show for their dominance.
It was a sweet moment for the Australian, whose goal was his first since February. He would have been hard pressed to miss, though, after Jamie Carragher had beaten Mark Delaney in the air to head Gerrard's free-kick back across goal. Sorensen made only a token jump and Kewell nodded home.
But in Solano, Villa have a player whose presence can never be discounted. And after Gavin McCann had accepted the temptation to go to ground under Carragher's challenge 25 yards from goal, the Peruvian brought his dead ball skills into play, curling the free-kick over the Liverpool wall and beyond the reach of Chris Kirkland.