When we talk about the 2011-12 Premier League title race, it's hard to look beyond the final day drama where Sergio Aguero delivered Manchester City their first Premier League title in stoppage time.
However, a few weeks before those events, Manchester United had what looked like an unassailable lead. A big shift happened in the middle, though, and it started with a short trip to Wigan to face Roberto Martinez's relegation-fighting Latics.
At the time, the result looked like a setback but not a dramatic one. However, as Mirror Football takes a look back 10 years on from that night, it serves as a warning sign for any team who thinks they have it all wrapped up with weeks to go.
With six games of the 2011-12 season remaining, United held an eight point lead over City. That's not the kind of gap you make up, and it's certainly not the kind Fergie's sides tended to throw away.
United opened that gap thanks to City's failure to win in three. After draws against Stoke and Sunderland, Mikel Arteta's late winner for Arsenal at the Emirates Stadium had seemingly wrapped it all up.
Wigan, in the bottom three on goal difference at the time of the game, weren't expected to do Roberto Mancini's team any favours. Indeed, there was still plenty of work to do after those midweek fixtures, but this was where it all started to unravel for United.
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If you were to look at the history books for good omens for Wigan, you'd have come up empty. In 14 previous meetings with Manchester United, they had lost 14 times, scoring just four goals along the way.
However, there was something about Wigan sides under Martinez which ensured they didn't know how to give up on a season. Comebacks from 2-0 down against Arsenal in April 2010 and West Ham in May 2011 were enough to keep them up in the Spanish manager's first two seasons, and the survival wheels were already in motion before they beat United.
After a run of one win in 14 threatened to lead the Latics towards the trap door, summer signing Shaun Maloney scored his first goal for the club in March to deliver a surprise win at Anfield. Two-and-a-half weeks later, Maloney was the hero once more as the league leaders came to town.
The goal was a great one from Wigan's perspective but a poor one for United to concede. Maloney showed great awareness to collect the ball from Jean Beausejour after a short corner and dart into the area before dropping a shoulder and curling beyond David de Gea, but the defenders may have felt they were slow to close him down.
Ferguson wasn't happy either, suggesting the corner should have been a goal-kick, and also criticised referee Phil Dowd for missing a Wigan handball in the area which could have changed the result. However, despite all this, the manager refused to go as far as saying the result was unfair.
Indeed, it was far from being all United. Victor Moses had the ball in the net for Wigan earlier in the game, with the goal chalked off for a foul, and the home defenders did a solid job against a forward line featuring Wayne Rooney and Javier Hernandez.
"Phil Dowd had a bad game and never got to grips with it, but Wigan were the better team and deserved it," Ferguson said. "It was one of these off-nights. It is unavoidable sometimes."
While United were floundering, City were romping to victory over West Bromwich Albion. And their victory, like Wigan's, owed a lot to a man who finished the season far more strongly than he started it.
Carlos Tevez had left Mancini seething after seemingly refusing to come off the bench in the Champions League in September. The Argentine would later claim it was a misunderstanding, but he would not play another minute for the club until March.
The West Brom game brought his first goal of the season, with a hat-trick at Norwich following three days later to make City believe. However, Mancini was refusing to get carried away after United's Wigan setback.
"I think United have a fantastic spirit, we don't have the same spirit and for this reason I think it is very difficult," the Italian said. The gap was five points with five games left, rather than eight and six, but he still made it out to be unassailable.
"I don't know because football is really strange," Mancini continued. "When you think one thing the opposite can happen. United is a really top team and I don't think they can lose the title."
Mancini was right when he suggested United would win their next game, with Aston Villa brushed aside in a 4-0 win for Ferguson's men. The following week would bring the next twist, however, as the Red Devils squandered a 4-2 lead to only draw with Everton.
City still had work to do, most notably beating United in what Fergie called "the derby game of all derby games" at the Etihad. In the end, they closed out the season with 18 points from a possible 18, with United's 10 points leaving them painfully short.
It was an incredible comeback, and arguably one of the best in Premier League history. However, without United opening the door by losing to Wigan, it would have counted for nothing.
