As Chelsea goalkeeper Petr Cech accepted in his own words, "At the moment of the shot, I didn't see the ball at all".
That was enough to undo Chelsea's hard work in the past three weeks. The match against Wigan was seen as a net practice for their midweek crunch derby against Tottenham. But what Chelsea displayed at DW Stadium against Wigan was nowhere near impressive.
Chelsea not only conceded a late equaliser, but also might have conceded their title challenges. With wins for both Manchester clubs on Sunday, the Blues moved further away from their title hopes. Moreover, derby rivals Tottenham scored a morale victory by leapfrogging Chelsea to third place in the league position having a game in hand.
The win against Manchester City had showed some deficiencies in the present Chelsea squad, but Saturday's stale draw exposed those problems glaringly.
In the following slides, we shall take a look into the five lessons learnt from Chelsea's lacklustre performance against an inspired Latics side.