Jose Mourinho sparked a huge tunnel bust-up at Stamford Bridge on Saturday after allegedly branding West Bromwich Albion "a Mickey Mouse club with Mickey Mouse players".
Mourinho was confronted by furious Albion defender Jonas Olsson after making the remark as the two teams left the field and it is understood there was a brawl involving almost 20 players, with Chelsea stewards required to act as peacemakers.
Olsson and Mourinho squared up to each other outside the dressing-rooms and had to be pulled apart by team-mates and stewards after the Chelsea manager's comment infuriated the Sweden international. Gareth McAuley and another Albion player also confronted Mourinho before they were calmed down by team-mates and returned to the visitors' dressing-room.
West Brom were already frustrated after Andre Marriner controversially awarded a 94th-minute penalty, which was converted by Eden Hazard to secure a point, to prevent Steve Clarke's team from registering their first league win at Chelsea since 1978.
Mourinho was walking back to the dressing-room when he is believed to have made the "Mickey Mouse" insult, resulting in angry scenes between the two groups of players. He made other derogatory comments during his stand-up row with Olsson before the pair were separated, although they later shook hands before Albion boarded the team coach. Mourinho later sniped at Albion in his post-match press conference, insisting "they are a team to finish in mid-table, every point for them is a great point".
Clarke's team, however, have already won at Manchester United this season and came agonisingly close to condemning Mourinho to his first ever Premier League defeat at Stamford Bridge. The visitors had led 2-1 for more than 25 minutes before Ramires fell over in the box after a coming together with Steven Reid, with Marriner pointing to the spot and sparing Mourinho.
The performance of Marriner, the Birmingham-based official, infuriated the Albion players and coaching staff after he was drafted in as a late replacement for Lee Probert, who was ruled out with a knee injury.
Marriner has not apologised to Clarke for the contentious penalty decision and is not believed to have included the post-match trouble in his official match report.
It is the second time this season that Mourinho has infuriated opponents at Stamford Bridge, after he was sent to the stands late in the 4-1 win over Cardiff in October by referee Anthony Taylor. He was also fined £8,000 for improper conduct.
Clarke, Mourinho's former assistant who helped the club lift two league titles, an FA Cup and two league cups, was not involved in the scenes in the tunnel and has urged his players to recover from Saturday evening's controversy.
He said: "We had the three points in the palm of our hand and it was taken away quite cruelly. So I'm angry, frustrated and sad for my team because they deserved to break another hoodoo.
"It was 1978 that we last had a win at Stamford Bridge and it would have been great to break that hoodoo like we did earlier in the season at Old Trafford.
"I don't think you can linger or look back for too long. We have to just move on, take all the good bits from this game and move on to what should be a good derby against Villa. Referees are human and I'm not one for criticising them but I hope over the course of the season we get our fair share of decisions."
Chelsea were unavailable for comment about the incident last night.