When the mob turn they tend to do so in an instant, as Avram Grant discovered to his cost last night. The boos that greeted the end of a goalless first half acquired a hard and angry edge when Emile Heskey scored a dramatic equaliser in the second minute of stoppage time, dealing a huge blow to Chelsea’s championship chances and gifting Manchester United control of the Barclays Premier League title race.

Steve Bruce’s celebrations at the goal that could secure Wigan Athletic’s Premier League future were thoroughly merited, but the biggest winner of the evening was his former manager, Sir Alex Ferguson, whose United side hold a five-point lead with only four matches remaining.

Chelsea got what they deserved after a dreadful first half and a lack of ruthlessness in the second after Michael Essien had given them the lead in the 55th minute. The unpalatable prospect of United retaining their title at Stamford Bridge on Saturday week is a suitably brutal punishment. Grant’s fate could be far worse, although given the extraordinary storylines and sub-plots that repeatedly consume this remarkable club the notion of him saving himself by winning the Champions League cannot be discounted.

The home jury appears to have already returned its verdict, however, and seems to be in agreement about his fate, with those closest to the dugout abusing the first-team coach with shouts of: “You don’t know what you're doing".

Grant's gamble in making five unforced changes from the side who beat Fenerbahçe last week backfired - with Bruce, the Wigan manager, pointing out that the absence of Joe Cole in the first half gave the visiting team a huge help - but circumstances also conspired against him, particularly in the withdrawals of Frank Lampard and Didier Drogba.

Chelsea were grateful for the remarkable return of Petr Cech, likened to Zorro by the club’s eccentric stadium announcer, but performing heroics more reminiscent of The Man in the Iron Mask in making a late save from Antoine Sibierski before Heskey’s equaliser. Suspicions that Grant was skating on thin ice had been confirmed during an inauspicious opening, which was subdued even by the standards of many matches at Stamford Bridge.

The Chelsea fans were so bored during an opening 45 minutes that ended with boos being directed at their own players that they resorted to singing tiresome songs about Liverpool slums, suggesting that they too had their minds on other matches to come.

Chelsea’s only real chances of the first half fell to Nicolas Anelka, who for all his class has yet to make a significant contribution for his new club since his £15 million move from Bolton Wanderers in January. Anelka scored 11 goals in a poor Bolton side before Christmas, but has managed just two for Chelsea - not least because he is used mainly as an understudy to Drogba – and the lack of sharpness showed.

The France striker wasted a great opportunity in the fifth minute when he headed Salomon Kalou’s cross across the face of goal, but was unfortunate to be denied 22 minutes later when Chris Kirkland, the Wigan goalkeeper, made a brilliant diving save to his right from another close-range effort.

Anelka was not helped by an appalling lack of support from his wingers, with Florent Malouda so poor on his first league start for two months that he was substituted at half-time. The France winger has bags of ability as he demonstrated against England in Paris last month, but question marks remain about his attitude.

It was not as if Chelsea had any reason to be complacent as Wigan also enjoyed a period of sustained pressure that, with more fortune, could have yielded a goal. Paul Scharner had a shot blocked by Alex, but the best chance fell to Antonio Valencia, who brought a smart save from Cech low down at his near post. Not for the first time, Chelsea were indebted to his bravery.

The introduction of the effervescent Joe Cole in place of Malouda at half-time succeeded in raising Chelsea’s tempo, as if they remembered that they were still in contention. The England player is irrepressible even when out of form and made an immediate impact, lifting the crowd’s spirits with a shot across goal in the 46th minute. Cole’s teammates responded to his seemingly endless energy, with John Terry hitting the bar with a left-foot volley and Kalou denied by another great save from Kirkland before the damn broke. Cole, inevitably, was the creator, crossing from the right to Anelka, who held the ball up long enough to create the space for Essien to score with a neat drive from the edge of the area.

Essien had a chance to win the game, but failed to beat Kirkland and Heskey made him pay a heavy price. As always with Chelsea they cannot be written off, but two matches in the space of six days in Liverpool is not a mission they will undertake with high hopes given their recent history of misery on Merseyside.

Chelsea (4-3-3): P Cech – J Belletti, Alex, J Terry, W Bridge - M Essien, J O Mikel (sub: A Shevchenko, 90min), M Ballack – S Kalou, N Anelka, F Malouda (sub: J Cole, 45). Substitutes not used: Hilário, C Pizarro, S Wright-Phillips.

Wigan Athletic (4-4-2): C Kirkland – M Melchiot, E Boyce, P Scharner, K Kilbane – L A Valencia, J Skoko (sub: J Koumas, 56), W Palacios, R Taylor (sub: M King, 79) – E Heskey, M Bent (sub: A Sibierski, 64). Substitutes not used: M Pollitt, M Brown. Booked: Koumas, Valencia.

Referee: A Marriner.