Houllier, who is recovering from chest pains in hospital, paid Sunderland an initial ?18 million for Bent in January and he scored his seventh goal in 12 games for Villa this afternoon.
That cancelled out the opening goal from another former Black Cats forward, Kenwyne Jones. Villa have now taken eight points from the last four games to virtually ensure another season of top-flight football.
Jones broke the deadlock when climbed above the Villa defence to head past Brad Friedel into the corner of the net.
It was against the run of play that Bent brought Villa back on level terms in the 43rd minute.
Kyle Walker crossed from the right and Bent got in front of Ryan Shawcross to glance a header from 15 yards past the diving Asmir Begovic and into the net via the post.
Source: PA
Source: PA