Manchester United's win over Liverpool on Saturday had moved them ahead of Roberto Mancini's side, but City held their nerve in a tense game at Villa Park and made their dominance count midway through the second half thanks to Lescott's cool finish.
That was enough to make it back-to-back league victories for City after their recent setback at Everton.
Annd they may yet be further boosted by the return of Carlos Tevez after Mancini admitted in the build-up to the match there could be a way back for the Argentina striker despite his fall-out with the Italian over his refusal to warm-up during a Champions League tie at Bayern Munich in September.
Villa, meanwhile, are now seven league matches without a win at home -- their worst ever run in the Premier League -- leaving Alex McLeish's side in danger of being dragged into a relegation battle.
Vincent Kompany returned from a knee injury to skipper City, who also handed a recall to ex-Villa midfielder James Milner.
McLeish, the subject of protests from around 100 Villa fans calling for him to be sacked before kick-off, made four changes with Charles N'Zogbia and Stephen Ireland, who were both caught up in controversy during and after last weekend's defeat to Newcastle, among those dropped.
Having hit the goal trail again against Fulham last weekend, Sergio Aguero took just three minutes to be presented with his first chance, the striker chested David Silva's cushioned headed only to fire a snapshot straight at Shay Given.
The early evidence suggested set-pieces represented Villa's best chance of scoring and their only real opportunity of the half came in the 18th minute when a Richard Dunne header from Stiliyan Petrov's delivery was plucked out of the air by Joe Hart.
Within seconds City had broken down the opposite end yet, having outfoxed Gary Gardner, Silva's tame attempt was easily saved by Given.
City were in total control and Villa were lucky to escape in the 27th minute when Stiliyan Petrov backed off Adam Johnson and the City winger's shot cannoned off the foot of the right post.
All that Mancini's side's lacked was a killer final touch, with Aguero twice spurning further opportunities and Aleksandar Kolarov curling a free-kick over the crossbar.
City continued to have the better of the possession and the chances after half-time but once again were thwarted by a combination of Villa's resolute defending and their own wasteful finish.
Vincent Kompany connected cleanly with a Milner corner but saw his goalbound attempt headed clear by Alan Hutton, then Given got his body behind a stinging Pablo Zabaleta drive after the play had been moved from left to right.
However, the hosts' resistance was finally broken in the 63rd minute when two former Villa players combined to set up Lescott.
Milner's corner to the back post was nodded back across goal by Gareth Barry and the defender was on hand to hook home from close range.
Despite continuing to dominate, City failed to double their advantage and they almost paid dearly when Darren Bent's close-range effort drew a fine stop from Hart.