The cynics who frequent Summerbee's bar and other mischief-makers around Eastlands are fond of a theory that Patrick Vieira is Roberto Mancini's obscenely well-paid dressing-room stooge. The Frenchman is staring at his 35th birthday and will not present a counter- argument that his best days are certainly behind him, but he provided something far more precious for his Italian manager than alleged player tittle-tattle and eased the sense of embarrassment for the England goalkeeper, Joe Hart.
Hart has turned more things into gold than Midas since his elevation to first-choice goalkeeper ahead of Shay Given this season. He has rewarded Mancini's faith and proved himself to be the most competent young goalkeeper in the country with some confident displays for England. But the impetuosity of youth can be a risky business, and that was demonstrated with catastrophic consequences by Hart's awful first-half mix-up with Kolo Touré that left City staring at the prospect of a second straight defeat.
The England international was 30 yards from his goalline when he suffered a communication breakdown with Touré in attempting to deal with Morten Gamst Pedersen's industrial punt. Both players failed to deal with the situation and Nikola Kalinic stole the ball for the easiest goal he will score all season.
"This is a fluke, it can happen in football," City's manager said. "Joe Hart is a good goalkeeper, but I hope after today we finish making gifts to the opponent."
Vieira, on his first Premier League start this season, emerged from his own first-half tribulations and a performance that made him look far off the pace with a reprise of his heady days at Arsenal. The speed may be slower, but the stride length remains unmistakable. He covered the ground from Blackburn's half of the centre circle into their six-yard box effortlessly and tapped in Carlos Tevez's return pass after two would-be markers abandoned their responsibilities.
The point brought some relief, but City's start has been far from the impressive one their owners dreamt of. Only one win in their first four games means they are already seven points behind the leaders, Chelsea, and they are nowhere near the kind of ruthless, efficient unit that Mancini needs.
If they continue to squander the number of chances they created here, the League title will remain as far away as ever. "We are very unlucky because we are missing a lot of important players through injury and we conceded a strange goal and after that we had 25 chances to score," Mancini said. "We must accept this result and continue to work."
Many of the chances foundered at the fingertips and hands of Paul Robinson before Christopher Samba underlined the determination and sense of team spirit Rovers have and City are still trying to generate, with a wonderful goalline block to deny the Brazilian striker Jo.
Afterwards Rovers' manager, Sam Allardyce, said: "It was a great performance, and the immense difference between both clubs is we've measured up to a team that should have brushed us aside in terms of the quality they can afford and the wages they can pay and the limited budget that we work on. For Manchester City it was an upset but [it was] a well-deserved result for us."
Allardyce is entitled to feel satisfied. Whereas City spent £125 million on players over the summer, Blackburn's only transfer expenditure was a nominal fee for a youth player. But there was no need for the antics of El-Hadji Diouf after the final whistle. His provocative blowing of kisses to the main stand and kissing of his armpits in a celebration intended to wind up his hosts were beyond acceptance.
It led to a water bottle being thrown in his direction, and City may yet find themselves the subject of a police investigation for the minor incident.
Substitutes: Man City: Jo for Wright-Phillips (57), Barry for Vieira (66), Silva for A Johnson (85). Blackburn: Olsson for Nelsen (40), Chimbonda for Salgado (46), Nzonzi for Grella (57).
Bookings: Man City: Yaya Touré, Vieira. Blackburn: Chimbonda.
Referee: Mark Clattenburg
Man of the match: Robinson