O'Leary, in his 100th game and 900th day in charge, could only cringe as Liverpool sealed their first Premiership away win of the season with two late goals, a Steven Gerrard penalty and a piledriver from Xabi Alonso.
As a result of their late surge, which never looked on the cards, Liverpool were able to extend their impressive record at Villa Park, where they have been unbeaten in the last eight years.
It was not quite a storybook return for Peter Crouch to his old club but he was the player who dramatically changed the course of the game after coming on as a substitute in the 68th minute.
Crouch had been left out by Liverpool boss, Rafael Benitez, as he had struggled since his arrival from Southampton. Without a single goal to his credit Crouch had to sit on the sidelines as Liverpool attempted to find some consistency, but eventually he made his mark on the game.
But Liverpool's inconsistencies were still evident in their early play as Gerrard, playing in his 300th game for the Reds, attempted to stamp his mark on the proceedings.
There was one excellent inter-passing movement involving the Liverpool skipper when Villa's defenders could only watch as the ball went backwards and forwards before Luis Garcia shot just wide from the edge of the area.
The threat of Gerrard was always present. His speed, tenacity and ability to finish was always a major concern as emphasised when he broke down the right only to be impeded by Gareth Barry who subsequently collected the first yellow card of the game for his obvious transgression.
Barry was included in the left-back role as Jlloyd Samuel paid the price for the poor performance in the loss at Manchester City.
To his credit, Barry had one of his better games in a defensive position when he often faced the formidable duel threat of Gerrard and Djibril Cisse.
Olof Mellberg and Liam Ridgewell, who were both castigated by O'Leary after the 3-1 defeat at Manchester City, certainly played with more fire and aggression against the star-studded Liverpool attack.
Villa, however, had to play second fiddle as they struggled to get to grips with the opposition.
Milan Baros, who had previously only made six appearances for Villa since his move from Liverpool in September, was given few opportunities to shine against his former colleagues as he was generally kept in tight check by Jamie Carragher and Sami Hyypia.
The individual brilliance of Gerrard continued to dominate the game as he demonstrated in devastating fashion with a perfect pass which left Villa's defenders completely stranded in midfield.
Cisse was allowed to run through unchecked and only the bravery of Thomas Sorensen foiled the Liverpool striker, who shot straight at the advancing Villa keeper.
The miss by Cisse, who was moved on to the right in an attempt to exploit Barry's lack of pace, only emphasised the fact that Liverpool struggled to move up a gear.
An increasingly frustrated Benitez sent on Bolo Zenden for Garcia ten minutes into the second half and it certainly created problems, but it was not until the last 20 minutes that the game came to life.
The sudden change occurred with the introduction of Juan Pablo Angel for Villa and the decision to put on Crouch for Morientes.
Angel very nearly set-up Baros, while Crouch produced a cross from the right for Gerrard to fire in a low shot which Sorensen brilliantly pushed away.
The Reds' best chance fell to Crouch, who is still to open his account for the European champions. He was perfectly placed for Zenden's cross only to see his close-range header go straight into the waiting arms of Sorensen.
The dramatic turning point occurred in the 85th minute when Crouch finished in a heap under Ridgewell's challenge and Gerrard slotted home the resulting penalty with precision.
Lifted by the goal Liverpool finished off the game in style when Alonso hammered home a low drive past the helpless Sorensen a minute from time.
Man of the Match: Steve Gerrard
The England midfielder was head and shoulders above the other players and it was his contribution which enabled Liverpool to pick up maximum points away from home for the first time in six months.