Former Premier League referee Mark Clattenburg has revealed an altercation with Jose Mourinho that left the Portuguese boss stunned white.
Clattenburg, who spent 13 years officiating in the top flight, took charge of countless matches during Mourinho's time in England and had a front row seat for his fall from grace in the eyes of the football public.
Once heralded as the 'Special One', able to bend the media and opponents alike to his will with his quick wit and charm, Mourinho's spells at Manchester United and Tottenham after his stunning success at Chelsea were largely marked by controversy.
Clattenburg has now detailed one such flashpoint with the 'unique' Portuguese when Mourinho stormed into his dressing room convinced the official had wronged his United side.
'He believed that I'd missed a handball by [Stoke's] Ryan Shawcross,' Clattenburg said on Daily Mail Sport's Whistleblowers podcast.
'He was adamant it was a penalty and said 'have you seen it on the replay?'. He said yes and then I just threw my boot in anger towards his direction.
Former Premier League referee Mark Clattenburg has revealed an altercation with Jose Mourinho that left the Portuguese boss stunned white
Clattenburg, who spent 13 years officiating in the top flight, took charge of countless matches during Mourinho's time in England
'I missed him of course. He went white, didn't know what to say and left the dressing room.
'When I got back home I watched the incident and he hadn't handled it. It was all mind games, bitterness and nastiness.
'In the end my relationship with Jose was less than it was when he was at Chelsea and he had that charm. Everybody loved him and called him the Special One.'
Mourinho was unveiled as Benfica manager last Thursday, signing a two-year contract at the club where he started his managerial career in 2000.
The Portuguese coach has been out of work since being sacked by Fenerbahce last month after their failure to qualify for the Champions League, before opting to replace Bruno Lage at the Lisbon club.
In contrast to his famous first statement as Blues boss in 2004, Mourinho admitted that he is 'less egocentric' than during his early years. He said he is now focused on bettering Benfica's players and the club as a whole.
'I am not important,' Mourinho said during his unveiling. 'We all change, and we change for the better. I am more altruistic and I'm less egocentric now, I think less about myself and more about what good I can do for others, the joy that I can bring to others. I am not important, Benfica is important.
'The Benfica fans are important. They are the heart of the club, but at Benfica, even more in a way. The players are important. I am here to serve.'
Mourinho was unveiled as Benfica manager last Thursday, signing a two-year contract at the club where he started his managerial career in 2000
His comments mark a striking shift from the uber-confident persona he has projected for most of his career.
Clattenburg also recalled how Mourinho tried to influence referees as soon as he arrived in England more than two decades ago.
'I remember his first comments about me, I refereed one of his first games and he was always on the charm, always saying how good referees were, always trying to get that edge,' Clattenburg added.
'I remember going to Real Madrid when he was serving a one match ban and he sent a message to my hotel wishing me all the best. It was always the charm, there was always something behind it.
'But when he wasn't so successful, he changed so much. In Turkey, he got so bitter, he was fighting with referees all the time. He didn't seem to have that charm anymore, probably because he wasn't winning.'