Ali Al Habsi's horrendous first-half mistake allowed David Silva to grab a winner for the hosts with his fifth goal of the season that allowed them to profit from Arsenal's failure to beat Sunderland and close to within four points of the Gunners.
For Toure though, it can only be small consolation following confirmation of a failed drugs test that potentially leaves him battling to salvage his career.
Immediately before the game, manager Roberto Mancini confirmed Arsene Wenger's view that Toure's mental state was "not great".
City officials had not expected the 29-year-old to be in attendance to watch his team-mates in action. But Toure was there, although any enjoyment could surely only have been partial.
At least he was not the only person under the spotlight.
As he contemplated his own blunder, Al Habsi must have felt equally alone.
After all, rock-bottom Wigan had performed superbly up to the point in the 38th minute when Silva skipped past Adrian Lopez, who chose just the wrong time to slip, and burst into the box.
The Spain star's shot was accurate but lacked power.
That did not matter though as Al Habsi inexplicably allowed the ball to squirm from his grasp and trundle over the line, leaving the Oman international to hold his head in his hands in agony.
Although City had enjoyed plenty of possession, they had only created one other chance, when Mario Balotelli cut in from the left flank in the opening minutes.
On that occasion, Al Habsi performed more in keeping with his general standards since arriving on loan from Bolton, making an excellent save, even if the ball did rocket away at a strange angle.
Apart from that, Wigan were virtually foot perfect.
After appearing in the headlines last week as the unwitting fall-guy in the Wayne Rooney elbowing controversy, James McCarthy's name should have been in lights again when Vincent Kompany's weak clearance rolled straight to him.
From 10 yards and in plenty of space, the very least McCarthy should have done was keep his effort on target.
He failed. The shot drifted badly wide, McCarthy scarcely able to believe what he had done.
City gave up a half-time lead right after the re-start against Fulham on Sunday and nearly did exactly the same again.
Antolin Alcaraz crept into space to meet Ben Watson's corner at the near post, flicking the ball over Pablo Zabaleta and onto the crossbar.
It was the high point of a lacklustre opening to a half both sides had so much incentive to do far better in.
The home supporters were starting to sense a problem when McCarthy let fly with a fizzing half-volley from 25 yards that brought an excellent save out of Joe Hart.
Alcaraz burst the full length of the field after robbing Yaya Toure, which was not only an indication of Wigan's growing confidence but also the space they were being afforded.
The Latics consistent failing this season though has been their inability to score.
This represented the 11th time this term they have failed to find the net, a failing that is going to get them relegated if they do not rectify it quickly.
Substitute Charles N'Zogbia was not able to as he sent a 20-yard shot flying over the bar.
If there was precious little else for City's supporters to cheer, they could at least herald the return of combative midfielder Nigel de Jong from an ankle injury seven minutes from time.
With a trip to Kiev on Thursday for a Europa League meeting with Dynamo, City need everyone available at present because they cannot count on more gifts like the one Al Habsi offered.
Dubliner Conor Sammon had one last chance of claiming the point Wigan deserved when he was sent through by Rodallega but his shot rolled agonisingly wide of the far post to leave Roberto Martinez cursing his luck once more.