An injury time goal from substitute Ross Barkley earned Chelsea a last-gasp 2-2 draw at home to Manchester United in the English Premier League in a match that ended with United boss Jose Mourinho involved in scuffles.
Two goals from Anthony Martial had appeared to have earned Mourinho's Manchester United a comeback win after they went 1-0 down in the first half.
Yet Barkley's 96th minute equaliser, which preserved Chelsea's unbeaten record, also prompted drama at pitchside as one of the assistants of Chelsea manager Maurizio Sarri seemingly provoked Mourinho.
Mourinho was outraged, rose from his seat and tried to confront the assistant, who appeared to disappear down the tunnel, and the United boss had to be restrained by officials.
Afterwards, Mourinho told Sky Sports that Sarri's assistant had apologised to him and he had accepted.
But the under-pressure United boss, who had looked set to earn a major win on the road until Barkley's late intervention robbed United of victory, described the late setback as an "awful" result for his side.
United, who had never won nor even scored a goal under Mourinho at his former club, went behind in the 20th minute when Germany defender Toni Rudiger strode away from marker Paul Pogba and rose to head home a Willian corner.
Chelsea had most possession and looked in control until Martial thumped in the equaliser in the 55th minute against the run of play after Chelsea goalkeeper Kepa Arrizabalaga had kept out a close-range Juan Mata shot.
The goal galvanised the visitors and Martial made it two in the 73rd minute after a fine breakaway move between former Chelsea midfielder Mata and Marcus Rashford.
At the other end David De Gea was forced into fine diving saves from David Luiz and N'Golo Kante but was powerless as Barkley hammered home after Luiz's header hit the post.
Mourinho, who won three titles with Chelsea, has been touted as the next Premier League managerial sacking after his side's uncertain start to the season but despite United's vastly improved performance, he was left frustrated by the result.
"One point at Stamford Bridge is always a good result because it's so difficult for teams to win here but after the game, the way the game was, it's an awful result for us and a phenomenal result for them.
"The team played very well. And individually in the second half, they raised the bar. The attackers brought the game into a different dimension and the defenders had a solid performace. I'm realy pleased with the individuals."
Mourinho, who lived up to his promise not to celebrate unduly if United scored, said: "No, I don't think I got that respect back but that's not my responsibility.
"I have a certain level of education socially and in sport and what I did today, I would do in Porto, Madrid, Milan. I try to behave always the same way.
"But the reaction of the fans is up to them."
Of the incident involving Sarri's assistant, he added: "I'm not annoyed. His assistant came to me in Sarri's office and apologised to me. I said 'if you really feel it that way, and you want to apologise, of course I accept your apology. Forget it, because I've also made lots of mistakes in my career."