Winning while playing badly is supposed to be one of the happy habits title-winning teams possess. Instead it was the soon-to-be-dethroned champions who underperformed and overachieved. Losing while performing well can be a consolation in autumn but as spring blooms, it bodes badly. Wigan remain three points from safety and one of their games in hand is gone. As ever, their attempt at escapology will go right down to the wire.
On the brink of a draw, they were cruelly denied by a ruthless Carlos Tevez, powering between Paul Scharner and Jordi Gomez and lifting his shot past Joel Robles. It leaves Wigan in a perilous position and Manchester City in no-man's land, nowhere near Manchester United but with a comfortable cushion over Chelsea.
They had beaten both in their previous two games but, after raising their game for the other occupants of the top three positions, they were outplayed by the team in the bottom three. Nevertheless, scorelines have an eloquence and, interrupted only by the dismal defeat at Everton, recent results tell a tale of City improvement. It is eight wins in nine games for them and, not coincidentally, eight goals in nine for Tevez. His latest act of community service was to send the majority at the Etihad Stadium home happy. "He played really well, Carlos, he fought," said an otherwise nonplussed Roberto Mancini.
His warmest words were reserved for Wigan. "For 60 minutes, they played better than us," he accepted, showing solidarity with the other managerial Roberto, Athletic's Martinez. "They don't deserve to be relegated. They don't play the long ball, they try to play always and also because Martinez is a good manager."
The beaten Spaniard has long displayed an uncanny ability to remain optimistic, regardless of the league table. This was no exception. "I thought we were magnificent from start to finish," he said. "If we do that in every game, we will get a lot of points. I couldn't be prouder of the performance."
They were, he argued, technically and technically better. They limited City to two shots on target, he said - Robles saved the first, from Edin Dzeko, and Tevez converted the second - and fashioned a series of opportunities themselves.
The common denominator was the classy Shaun Maloney, whose enduring capacity to overshadow more vaunted talents was highlighted. The Scot supplied the instinctive, brilliant flick to send Franco di Santo clear; Joe Hart, who had displaced the FA Cup semi-final saviour Costel Pantilimon, saved just before half-time. Just after, Maloney defeated the goalkeeper, but not the covering Joleon Lescott, with a shot that was hacked off the line.
Smooth and fluent, Wigan flourished. Disjointed and below par, City did not. Mancini cited fatigue after their Wembley endeavours, though he was able to make five changes. Micah Richards' return after six months on the sidelines included a boot in the face from Jean Beausejour and a kick up the backside from his manager. "I didn't like it," he said, asked about the right-back's comeback.
Eventually, Richards made way, a minute before Tevez made hay. As the lesser-spotted Scott Sinclair entered, it seemed a desperate gamble by Mancini. Congenitally incapable of letting a game evolve without his interference, his impatience and analytical mind meant he spent the second half indulging in high-speed tactical tinkering.
He began with two defensive midfielders in the team - and a third was sat in the stands as Nigel de Jong visited his former club - which seemed a failed attempt to liberate Yaya Toure. Then, imitation proving the surest form of flattery and in a rare example of favourites switching tack to counter the underdogs, he swapped to a back three for a quarter of an hour. With that making little difference, Mancini reverted to a four-man defence.
But, whichever, Wigan found space between the lines. "I don't think they could handle the movement of Shaun, Franco, Jordi and Arouna [Kone]," Martinez added. He and his players departed with plaudits but no points, Mancini with plenty to ponder before the FA Cup final rematch on May 11. Because normally when these two teams play, Wigan wonder how to stop City. Now it might be the other way around.
MAN OF THE MATCH: James McCarthy. There were plenty of candidates, most of them from the visitors' ranks, but the Ireland international stood out. Terrific in possession, he is having an excellent season. It is not a question of if he leaves Wigan, but when.
MANCHESTER CITY VERDICT: Underwhelming. As expected, David Silva was not risked and should be fit for Sunday's trip to Tottenham. Of the understudies Mancini selected, Lescott was reliable in the centre of defence and Aleksandar Kolarov energetic on the left flank. Sergio Aguero, the headline act for the previous nine days, did not reappear for the second half, when Dzeko replaced him.
WIGAN VERDICT: Impressive, but the reality is they are running out of time. Unlike Mancini, Martinez cannot really rotate and Wigan face a third demanding game in eight days when they visit West Ham on Saturday. Martinez expects their season to go down to the final game, at home to Aston Villa. "To be able to play for everything at home is something we will embrace," he said.