Keane, a player most Wolves supporters feared would have moved onwards and upwards by now, struck on the half-hour, meeting Carl Robinson's flick- on and hammering a right-footed shot from a difficult angle between Nicky Weaver and his near post. For all the effort expended and the pressure exerted, it was not a finish you could visualise any of City's strikers matching.
Defeat was a poor reward for a performance that did not lack enterprise. From the start, City's priority was to get the ball to their wingers, Terry Cooke and the summer signing from Wimbledon, Mark Kennedy.
It was reminiscent of some of Joe Royle's buccaneering and highly successful Oldham sides, but an important side of the equation went missing when Danny Granville, on loan for three months from Leeds, went off after 14 minutes with a hamstring injury.
Even in his absence, and despite Haavard Flo hitting the post with a header, City continued to make the running. Gerard Wiekens almost forced in a Cooke free-kick, Mike Stowell made a flying one-handed save from Andy Morrison's header and Kennedy put a low cross right through the six- yard box.
Keane's beautifully taken goal jolted them out of their stride and, even when they tore into Wolves after the break, there was more quantity and quality about their attacks.
Amid a string of corners and a couple of frantic goalmouth scrambles, Wiekens had a header cleared off the line and Morrison put one just wide. A Wolves defence expertly marshalled by the 35-year-old former City captain Keith Curle and the equally impressive Neil Emblen was never seriously inconvenienced.
Even in the six minutes, generously added on by way of a last chance to retrieve the situation, City could not fashion the clear-cut opportunities they needed, although Gareth Taylor put a header over the bar.
"I don't think we've been at our best, but it's been a bit of a smash and grab from their point of view," Royle said.
The Wolves manager, Colin Lee, joked when a mobile phone rang during his press conference that the caller might be John Gregory, who has already had a pounds 5m bid on behalf of Aston Villa for Keane turned down.
Royle said before the game that the calibre of the opposition in their first half-dozen games would tell City much about the job that lies ahead in this division. Considering that Wolves are in one of their quieter phases and not widely expected to be battering the Premiership door down, this result will be a sobering start for City's ever expectant fans.
Manchester City (4-4-2): Weaver; Edghill, Wiekens, Morrison, Granville (Crooks, 14; Taylor, 69); Cooke, Whitley, Horlock, Kennedy; Goater, Dickov. Substitutes not used: Bishop, Allsopp, Wright (gk).
Wolverhampton Wanderers (4-4-2): Stowell; Muscat, Emblen, Curle, Naylor; Bazeley, Robinson, Osborn (Sedgley, 70), Sinton; (Simpson, 75) Flo, Keane (Corica, 81). Substitutes not used: Mautone (gk), Green.
Referee: T Heilbron (Newton Aycliffe).
Man of the match: Emblen.