The midfield player's spectacular winner against Sunderland made it seven successive home league victories for City, their best start to a season since 1902.
Ireland's strike midway through the second half finally broke the stalemate on what was an otherwise frustrating night for Sven-Goran Eriksson's side which struggled to break through a stubborn Sunderland defence.
Indeed, it looked for three-quarters of the match as though the Black Cats would pick up a valuable point in their battle against relegation.
City's goal followed their best move of a lack-lustre display in which they looked to be still suffering a reaction from their 6-0 defeat at Chelsea.
Martin Petrov sent a raking crossfield pass to Javier Garrido on the left and he released substitute Darius Vassell whose cross from the left side of the penalty area was volleyed home by Ireland from a tight angle.
There had been few Bonfire Night fireworks until that point in a match which must have been a turn-off for the live television viewers.
Sunderland had a great chance to snatch the lead in the opening period when Anthony Stokes headed narrowly wide from Grant Leadbitter's cross.
Yet late in the half City almost took the lead when Vedran Corluka's header from Petrov's corner beat keeper Craig Gordon only for Daryl Murphy to save the day with a goal-line clearance.
Eriksson brought on Vassell in place of Michael Johnson for the restart to try and inject more bite into their attack.
And it eventually paid dividends when Vassell helped set up Ireland's match-winning goal, his first of the season.
The goal provoked an immediate response from Sunderland who had their best spell of the match.
Leadbitter stole in at the far post and his shot beat keeper Joe Hart only to luckily strike captain Richard Dunne who was covering on the line.
Ross Wallace then delivered a superb low cross from the left which Kenwyne Jones, sliding in at the far post, narrowly failed to reach, as City endured some nervous moments defensively.
And though City were far from their best, they still secured a win which maintains their fine start to the season.