Chelsea and United players soon got involved themselves in what can only be described as spectacular scenes at Stamford Bridge. De Gea made a point-blank save only for substitute Barkley to turn home from close range - Mourinho then leaping from the bench after Ianni celebrated in front of the Portuguese.
But in his post-match press conference, Mourinho revealed Ianni had approached him in the tunnel after the match and apologised. If you say before the game that one point at Stamford Bridge is a good result, it is so hard to win here but after the game with the way the game was it is an bad result for us and a phenomenal result for them.
The Daily Mirror ran a back page story on the morning of United's last Premier League game against Newcastle claiming Mourinho would be sacked that weekend regardless of the result against Rafael Benitez's side.
He said: "I'm not annoyed with anything". What happened was with Sarri's assistant, Sarri was the first one to come to me and say he will resolve it. He was for the first time best player in the Premier League with me, so I think the feelings are good.
He later held up three fingers to the Chelsea crowd, signifying the three Premier League titles he won with the Blues. But the Chelsea manager did not know the precise nature of Ianni's actions until he spoke to Mourinho after the game.
"The manager told me to help the team win the game".
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Mourinho took his United side to former side Chelsea this afternoon, looking to kick on from the 3-2 win over Newcastle two weeks ago.
The goal was the latest United have conceded since 2009. "We work on the pitch, the analysis, the preparation", said Mourinho. But I have that situation immediately.
However, United fired back in the second half as Anthony Martial bagged a quick fire double, appearing to steal the points.
The dramatic finish was then overshadowed by the late scuffle, which had been instigated by Ianni's celebrations that Mourinho noted were "very impolite".
"I think I will try always to control myself and to respect the stadium and supporters that were my supporters and my stadium for many years".
In a match which epitomised the rich history of the Premier League's drama, Manchester United came away with just one point.
Mourinho demonstrated he can still provoke a reaction from these United players as they responded to his half-time talk with a transformed second-half display, full of pace, threat and intent, which took them to within seconds of an outstanding win.