Roberto Di Matteo and Sir Alex Ferguson had to be separated as Manchester United ended their 10-year wait for a Premier League win at Chelsea in the most controversial manner imaginable.
The Blues finished with nine men and were beaten by an offside winner as United made up for all the bad luck they perceived they had suffered at Stamford Bridge in one fell swoop to cut their opponents' lead at the top to one point.
Referee Mark 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.
Ferguson did not need to bother with mind games against Chelsea last season, so far adrift were they of United in the league.
But he did not waste any time prior to this fixture, branding the side built by Jose Mourinho seven years ago as better than the current league leaders, in defiance of the plaudits earned by Di Matteo's men this season.
His opposite number refused to be drawn into the phoney war, knowing the worst thing to do ahead of today's game was to stoke up any ill feeling.
Rio Ferdinand thought so too, duly wearing his 'Kick It Out' T-shirt during the warm-up and shaking Ashley Cole's hand before kick-off.
Ashley Young - a surprise starter after more than two months out injured - was the only player on either side to snub the anti-racism initiative, while the home supporters jeered and taunted Ferdinand mercilessly.
It had no effect on the defender, who was celebrating a two-goal lead after 12 minutes as United became the latest top side to ruthlessly expose Chelsea's shortcomings.
It took less than four minutes, the Blues losing possession and Van Persie crashing a shot against the post, the ball rebounding in off the luckless Luiz.
Ivanovic was fortunate to escape a booking for clattering into Young before United struck again, Ferdinand this time the architect.
The defender was predictably booed as he ambled out of defence and found Rafael, who fed Antonio Valencia, with the winger's low cross instantly swept home by Van Persie.
It was a goal of embarrassing ease against a Chelsea side Di Matteo had warned about the way they were starting games, but the European champions finally woke up midway through the half when Michael Carrick chopped down Ramires.
He should have been booked but Luiz almost punished him anyway with a brutal free-kick which David De Gea inexplicably elected to save with his legs, the Spaniard deviating from the goalkeeping coaching manual again to keep out Gary Cahill's header.
Torres was having another shocker but his failure to react to a corner missed by everyone else was forgivable and his header was only kept out by a brilliant De Gea save.
The goalkeeper could do nothing when Wayne Rooney needlessly upended Eden Hazard with a revenge tackle a minute from half-time - earning a booking - and Mata stepped up to curl a sumptuous free-kick into the corner.
Mata would have equalised moments later had De Gea not made amends for a horrendous clearance before Torres earned his first booking for a foul on Tom Cleverley.
But Chelsea needed only seven minutes of the second half to deservedly level as Mata took the game by the scruff of the neck.
After scuffing a right-foot shot, he showed sublime control to keep Oscar's ball in play, allowing the Brazilian to cross again for Ramires to head home.
Hazard had two more sniffs before United got a grip.
And they were given a golden opportunity to snatch all three points as disaster struck for Chelsea when Ivanovic and Torres were both sent off in the space of five minutes.
Ivanovic could have no complaints, the right-back seeing red for bringing down Young, who had been played clean through by Van Persie.
Rooney fired the resultant free-kick just over before United replaced the ineffective Cleverley with Javier Hernandez and Chelsea sent on Cesar Azpilicueta for Oscar.
They were about to bring on Daniel Sturridge for Torres but the striker joined Ivanovic in the dressing room when he was controversially shown a second yellow for diving when replays showed he had been caught by Evans.
Torres was furious, trudging off and berating the fourth official, who was then forced to keep Di Matteo and Ferguson apart on the touchline.
Ryan Bertrand joined the fray instead of Sturridge but Chelsea faced an impossible task with nine men and Hernandez snatched what proved the winner 15 minutes from time from an offside position.
Petr Cech brilliantly tipped Van Persie's shot onto the post but Rafael followed up and Hernandez turned the ball home.
Mikel was booked for his protest, Sturridge entered the fray and Valencia also saw yellow as well as wasting a chance to kill the contest.