Bent, signed for a club record fee from Sunderland earlier this week, made an immediate impact at Villa Park by firing the hosts in front after 18 minutes, reacting quickest when Ashley Young’s initial shot was parried by City goalkeeper Joe Hart.
In response, City defender Vincent Kompany brought a decent save out of Brad Friedel before former Villa man Gareth Barry glances a header agonisingly wide.
Hart kept his side in it by saving efforts from Ashley Young and Stewart Downing, while City’s big-money January signing Edin Dzeko headed wide at the other end.
Young again challenged Hart with a long-range shot as Villa tried to double their advantage, but a second did not come and they were forced to fight a rearguard action in the final 10 minutes.
Ciaran Clark deflected a Nigel de Jong effort onto his own upright before Dzeko again headed wide, and Villa, led by James Collins and Richard Dunne, held on to claim three points that lifted them out of the relegation zone.