Villa have injected fresh life into their survival bid with a decent run of form, thumping Sunderland 6-1 on Monday night, and they did enough to merit another maximum-points haul with two fine goals from Gabriel gbonlahor in the second half.
The Villa winger had drilled in a superb 25-yard effort on 55 minutes, which was cancelled out by a penalty from Norwich captain Grant Holt.
However, Lambert - who had guided the Canaries to successive promotions back up into the top flight before an acrimonious departure last summer - enjoyed the last laugh as Agbonlahor rolled in a late winner which leaves his old club still looking anxiously over their shoulders heading into the final two matches.
Norwich boss Chris Hughton had again left out fit-again England goalkeeper John Ruddy as Mark Bunn retained his place, while Wes Hoolahan came into the side as Kei Kamara started the final match of his loan spell from the Major Soccer League as a substitute.
The home side started brightly, with wingers Anthony Pilkington and Robert Snodgrass dangerous down the flanks.Villa, however, looked dangerous on the break as Agbonlahor's shot was blocked behind.
Norwich floated a deep free-kick through the Villa penalty box towards the far post, where Ryan Bennett's downward header lacked any real pace to trouble goalkeeper Bradley Guzan.
Villa were forced into a change on 27 minutes when Matthew Lowton hobbled off, replaced by Eric Lichaj.
Joe Bennett tugged Snodgrass' shirt on the edge of the Villa box, with the Norwich midfielder hitting the resulting free-kick straight into the wall, before then testing Guzan as he lashed the rebounded back goalwards.
At the other end, Andreas Weimann's deflected cross had Bunn scrambling down quickly at his near post.
Norwich full-back Javier Garrido got forward on the overlap down the left, and his cross was just missed by Pilkington before being headed over by Grant Holt.
The Spaniard was then forced into some defensive duties as he blocked a cross from Agbonlahor which looped up and onto the top of the crossbar.
Villa opened up the Norwich defence at the start of the second half when Benteke waltzed into the penalty area, only to then shoot tamely at Bunn from 10 yards out.
The visitors did break the deadlock on 55 minutes.
Agbonlahor picked the ball up just inside the Norwich half and as the defenders back off, the Villa winger surged forwards before unleashing a superb strike into the bottom corner from 25 yards.
The midfielder ran over to celebrate with the jubilant Villa fans, while manager Lambert remained a figure of composure in the technical area.
Norwich looked for an immediate response, but Hoolahan failed to connect with a deep cross from the left after arriving unmarked at the back post.
Villa, though, should have made it 2-0 moments later when Agbonlahor darted away down the left and floated a lovely ball back across the face of goal - where Weimann somehow sent his half-volley over the bar from two yards.
Benteke and Norwich defender Sebastien Bassong got involved in an unnecessary confrontation, with both players raising hands and were somewhat fortunate to only be shown yellow cards.
With 20 minutes left, Kamara replaced Hoolahan - a change which was greeted with chants of "you don't know what you are doing" by some in the home crowd.
Not long after, those same supporters were in more positive mood as Holt equalised from the spot on 74 minutes.
Snodgrass got away down the right and cut back into the area, where he was bundled over by Bennett.
Holt had missed Norwich's only other penalty this season, in stoppage time here against Southampton, but he made no mistake this time as he crashed the ball into the bottom left corner.
Both sides pressed for what would be a crucial winner in their battle for Premier League safety.
And it was Agbonlahor who secured a crucial three points for Villa when he got goalside of Bassong, before rolling the ball into the far corner.
Norwich pressed in stoppage time, with Holt's header floating wide as Villa closed out for a hard-earned victory.