A spectacular overhead kick from Christian Benteke midway through the first half cancelled out Wes Hoolahan's well-worked opener, before the Belgian powered home a header two minutes later to give his side the lead.
Hoolahan spurned a great chance to level things soon afterwards, before Leandro Bacuna rounded off a wonderful sweeping counter-attack with a curled finish.
|VIEW FROM VILLA PARK
|By Sam Lee
There was not much to be positive about at Villa Park before kick-off and it looked like it was going to be a very long, frustrating afternoon for Paul Lambert against his former club, but despite Wes Hoolahan's opener and about 10 minutes of vociferous booing from the home crowd it all turned out rather well.
Christian Benteke was back to his best and scored a quick-fire double, before Leandro Bacuna added a fine third and Sebastien Bassong put through his own net.
The second half was a non-event but Lambert will be delighted to keep up his good record against his old club and to avoid the kind of headlines which would've put him under serious pressure had Villa lost.
For Norwich, who performed so admirably against Tottenham last time out, this was a disaster and questions about Chris Hughton's future will once again be asked.
Villa fans rarely leave Villa Park in a good mood these days but they will relish this one, which has kept the relegation wolf from the door - for the time being.
The victory eases the pressure on Villa boss Paul Lambert, ending a run of four games without a win, while condemning Norwich to their fifth consecutive away defeat.
Lambert had been keen to diffuse any tensions with his former employers in the build-up to the clash, which were rekindled after a publically unsuccessful pursuit of Hoolahan back in January.
And it was the 31-year old who broke the deadlock within the opening three minutes.
The onrushing Gary Hooper beat the offside trap to race away from the defence, before squaring to Hoolahan, who made no mistake from close range.
Shell-shocked Villa struggled to break down the visitors for long periods of the first half, but they were level 20 minutes before the break in spectacular fashion.
Ron Vlaar's long ball found Benteke in the box and, with his back to goal, the striker took a neat touch before lashing a stunning overhead kick past John Ruddy.
Benteke was on hand again two minutes later, shaking off Bassong in the area to head home Ashley Westwood's corner.
Hoolahan nearly levelled just a few minutes after, playing a one-two with Hooper to cut open the defence before being denied by a superb double save from Brad Guzan.
Norwich were made to pay for that missed opportunity eight minutes before half time, when a lightning-quick counter-attack saw Andreas Weimann play in Bacuna, who curled a terrific effort past Ruddy.
The hosts had a fourth just before the break, when Delph's cross was turned into his own net by Bassong.
They should have been celebrating again five minutes into the second half too, when a teasing Delph cross found the unmarked Gabriel Agbonlahor in the box, who inexplicably headed wide.
Weimann spurned another decent opportunity 15 minutes later, although Villa seemed content to take ease off as the game reached its conclusion.
Norwich brought on Sweden striker Johan Elmander in an attempt to inspire a fightback, and he had a chance to reduce the deficit late on before skewing wide after after good work from Martin Olsson.
Hooper went close five minutes from time, forcing a fine save from Guzan after being played clean through, but that miss summed up a frustrating game for the visitors.