Chelsea last night made a formal complaint against referee Mark Clattenburg after accusing him of using "inappropriate language" to two of their players in the controversial defeat to Manchester United.

The European champions confirmed they had reported Clattenburg to the Premier League match delegate for an alleged race slur after the fiery 3-2 loss at Stamford Bridge.

A club spokesman said: "We have lodged a complaint to the Premier League match delegate with regards to inappropriate language used by the referee and directed at two of our players in two separate incidents in today's match.

"The match delegate will pass the complaint to the FA. We will make no further comment."

Clattenburg today insisted he would co-operate with any probe.

Professional Game Match Officials (PGMO), the body which represents Premier League referees, released a statement which read: "PGMO is aware of the allegations and they are being treated with the utmost seriousness. Mark will co-operate fully and welcomes the opportunity for the facts to be established."

All four officials – the referee, his two assistants and the fourth official – wear microphones and ear pieces that allow them to hear what each other is saying throughout the match. What is said between them is not recorded.

The revelation that Chelsea had made the complaint rounded off a dramatic day which saw the Blues lose their unbeaten top-flight record after Javier Hernandez struck 15 minutes from time.

Hernandez's goal sparked wild celebrations among the United players which angered a section of the home support in the Matthew Harding stand.

Some Blues fans hurled abuse at the United players who had gathered to celebrate and there were reports some threw objects on to the pitch

A steward was injured during the incident and needed 10 minutes' treatment from paramedics.

Afterwards the club confirmed the steward had been taken to hospital. The incidents put the tin lid on a controversial match which saw Chelsea finish the game with nine men – and Man United end their 10-year wait for a Barclays Premier League win at Stamford Bridge.

Referee Clattenburg wrongly sent off Fernando Torres for diving after Chelsea had fought back from a David Luiz own goal and Robin van Persie's ninth of the season to equalise through Juan Mata and Ramires.

Branislav Ivanovic did rightly see red five minutes before Torres, whose second yellow card prompted furious exchanges between the rival managers, and that was before Javier Hernandez's winner.

But the result puts Sir Alex Ferguson's side within one point of Chelsea at the summit.

Blues boss Roberto Di Matteo said: "We are massively disappointed that these key decisions were wrong.

"It always seems to be in favour of the opposition.

"So it's a shame, because it was a good game of football with two good teams and the officials ruined it."

Told that Ferguson had slated Torres, Di Matteo said: "Listen, whatever he says, it was a foul in our favour."

He added of referee Clattenburg: "Surely when he's going to watch the images, he's going to realise that he made big mistakes."