After scoring a spectacular winner against Derby in the opening home league match, midfielder Johnson has this season become an indispensable figure in City's new look side.
And while manager Sven-Goran Eriksson has spent £40million on fresh talent, it has been home-produced players like Johnson, Micah Richards, Nedum Onuoha and Kasper Schmeichel who have caught the eye and won many plaudits.
City's finest start to the season saw Eriksson and Richards rewarded before kick-off as they received awards for being Premier League manager and player of the month for August.
While this was not one of City's most impressive displays of the season, they at least displayed battling qualities to grind out a victory having lost their last two league matches.
And City defended resolutely to keep a third successive clean sheet at Eastlands, where they have yet to concede a goal this season.
The opening period may have been end-to-end, but neither side had a cutting edge to put the finishing touch to some enterprising play.
The closest either side came to a goal came when Elano released Johnson who burst into the penalty area only for keeper Scott Carson to make a brilliant save.
And it was the same Elano and Johnson combination which finally unlocked the Villa defence for City's match-winning goal shortly after the restart.
Johnson took a return pass from Brazilian Elano and made a brilliant burst past three Villa players before coolly firing home from just inside the penalty area.
In stoppage time, substitute Rolando Bianchi almost doubled City's winning margin after he rounded keeper Carson only to see Gareth Barry make a goalline clearance.
Villa were far more livelier in attack in the second half as John Carew, Martin Laursen and Gabriel Agbonlahor all had decent attempts at goal, but none troubled keeper Schmeichel.
Ashley Young also had the ball in the net but what would have been an equalising goal was ruled out for a push by Luke Moore in the build-up.
It proved a frustrating afternoon for Villa whose run of three successive league and cup wins came to an end.