Sunderland may have benefited from uncharacteristically welcoming defending from Chelsea, whose title hopes are hanging by a thread after a shock defeat to the Premier League's bottom side, but the hospitality ended there.

Once José Mourinho, channelling his inner moody teenager as he struggled to deal with the shock of losing his 77-league game unbeaten run at Stamford Bridge, had finished making his displeasure known with Mike Dean's refereeing in a press conference that radiated sarcasm, the shutters came down. No questions please. Not today. We couldn't possibly speak at this difficult time. The injustice is still too raw.

Mourinho took no questions while no one else from Chelsea was available for comment – unless the club's exclusive interview on their official site with Nemanja Matic counts. The sense was that Mourinho, who spoke to the officials in the tunnel after the match, wanted only his words in the public domain and while it may be difficult to prove that his comments about Dean, who infuriated Chelsea with a number of questionable decisions, called the official's authority into question, it did not require forensic analysis to read between the lines.

Only the irredeemably naive would have thought Mourinho was being genuine when he congratulated Dean and the Mike Riley, the head of the Professional Game Match Officials Board. The Football Association is unlikely to be impressed with yet another reminder that Chelsea are not at their most gracious when they lose and there will certainly be punishment for Mourinho's assistant, Rui Faria, who had to be restrained from confronting Dean after he awarded the late penalty that allowed Fabio Borini to steal the points for Sunderland.

Faria, erupting as Chelsea's title challenge went up in smoke, was so incensed that Mourinho had to hold him back by his hair and Ramires can also expect a charge for violent conduct after Dean missed his elbow on Sebastian Larsson in the first half. The Brazilian midfielder would miss Chelsea's final three matches if he is found guilty.

The silence was deafening and it was not particularly surprising that Mourinho did not expose himself to being asked about Faria's conduct or Ramires's use of an elbow. Controversy continues to stalk the Chelsea manager, who is still appealing against the £8,000 fine imposed for misconduct after he was sent to the stands by Chris Foy during the defeat at Aston Villa last month.

As exercises in diversionary tactics go, this was a Mourinho masterclass. Dean was undeniably poor, at one point inadvertently starting a Sunderland attack, but Chelsea only have themselves to blame for falling five points behind Liverpool. Defeat at Anfield next Sunday would make it mathematically impossible for them to win the league.

It looked like it would be a breeze after Samuel Eto'o volleyed them into the lead but it was Mark Schwarzer, not Dean, who spilled Marcos Alonso's shot for Connor Wickham to equalise. It was César Azpilicueta, not Dean, who slipped and was penalised for bringing down Jozy Altidore.

Dean did not miss the chance that Demba Ba put wide of an open goal. Dean did not sell Juan Mata or fail to sign a top-class striker. Without the injured Eden Hazard, Chelsea lacked wit and invention against a deep defence. Dean did not fail to beat Sunderland, West Bromwich Albion and West Ham United at home, or lose at Villa and Crystal Palace. The fact that Chelsea have choked is what hurts most for Mourinho.

Their season is not over yet. The first leg of their Champions League semi-final against Atlético Madrid is on Tuesday and they will hope to have Petr Cech, who was missing on Saturday with a virus, and Hazard back at the Vicente Calderón.

As for Sunderland, a first win since 1 February has given them a fighting chance of staying up and they have taken four points from games against Chelsea and Manchester City. Dead and buried a week ago, they are now three points behind Norwich City in 17th place and have a game in hand.

The irony was that Sunderland's winner was scored by a player who is on loan from Liverpool. Borini, who said he was expecting a few texts from his team-mates back at Liverpool, has a knack of scoring important goals.

"I think the most difficult time was the last few crosses I was trying to head away as well," Sunderland's manager, Gus Poyet, said. "But on the penalty I was calm because I was confident in him."

At least someone inside Stamford Bridge kept his cool.

Man of the match Vito Mannone (Sunderland)