Less than a year after he left Old Trafford, Carlos Tevez can effectively finish Sir Alex Ferguson's Premier League title aspirations in the derby at Eastlands next weekend, and the noisy neighbours are in boisterous mood.
A day that started well for City supporters with United's title challenge suffering at Ewood Park ended in euphoric mood thanks to the double act of Tevez and Emmanuel Adebayor, who shared four goals to strengthen manager Roberto Mancini's grip on the final Champions League qualifying place.
The Italian believes Liverpool are no longer contenders. "It is probably between us and Spurs now," he said.
It has been a good week to be a City supporter: United knocked out of Europe and Ferguson virtually conceding the title to Chelsea. Defeat at Eastlands on Saturday would prompt more awkward questions over Tevez and United's refusal to pay the £25m to sign him permanently at the end of last season. Hindsight is a wonderful thing, but as the season unravels at Old Trafford it looks a poor decision now, especially when compared with the impact of Dimitar Berbatov, for a fee £5m higher.
Tevez's statistics will certainly be used as a beating stick. Twenty goals in his last 18 Premier League games and 28 goals in total dwarf the contribution of the Bulgarian across the city, and the significance of Saturday is not lost on Mancini.
"We want to win for our supporters and for our position in the league table. That is the most important thing," he said. After scoring 14 goals in their last three games confidence could not be higher – even if it goes against Mancini's more pragmatic Italian theories.
At times Birmingham were spellbound by City's movement and pace. "It seemed like they had extra men on the field. That is what good sides can do to you," said Alex McLeish, the Birmingham manager who will not have seen his resolute side capitulate in such a fashion at any stage previously this season. "We did not down tools, but there was some pretty dreadful defending at times," he added.
There was little indication of the Sabatier City were going to take to a well-drilled Birmingham defence that had frustrated them for 37 minutes, until Scott Dann's harmless nudge in the back of Adebayor, which gave Tevez the opportunity to showcase his penalty-taking skills and he collected his sixth of the season from 12 yards. Cue mayhem.
Nedum Ouonha flung himself to head Adam Johnson's corner but the ball brushed the bottom of Tevez's boot on its way beyond Maik Taylor. "He is desperate to finish top-scorer so he can have it," said Onuoha.
Republic of Ireland international Taylor was deputising for Joe Hart, who was not allowed to play against his parent club, but both of them in goal would not have made much difference to the outcome.
Cameron Jerome feigned brief Birmingham resistance by heading in James McFadden's cross, but that was wiped out within 60 seconds as Adebayor tapped in his first from Craig Bellamy's cross. There was little doubt the fourth City goal belonged to Onuoha, who finished with an aplomb Tevez would approve of before Adebayor ran from half-way to finish off the romp.
Throughout the Mancini scarf remained tightly twirled around his neck, despite Britain basking in the first real throes of spring this weekend, but it will be Ferguson who is hot under the collar at the prospect of visiting the neighbours this weekend. Welcome to Manchester, Alex.
Manchester City (4-4-2): Given, Onuoha, Kompany, Touré, Garrido; Johnson (Cunningham, 89), Barry, de Jong, Bellamy (Wright-Phillips, 80); Tevez (Santa Cruz, 87), Adebayor. Substitutes not used: Kay, Nielsen, Boyata, Ibrahim.
Birmingham City (4-4-1-1): Taylor; Carr (Larsson 57), Dann, Johnson, Ridgewell; Gardner, Bowyer, Ferguson, Fahey (Phillips 65); McFadden; Jerome (Benitez 72). Substitutes not used: Doyle, Michel, Parnaby, Vignal.
Referee: P Dowd (Staffordshire).
Booked: Birmingham City Johnson, Fahey, Jerome
Man of the match: Tevez