Maurizio Sarri decided to quit Chelsea after his own fans turned on him at Cardiff City Stadium, it is claimed.
The Sun report Sarri reached breaking point when Chelsea supporters began shouting "Sarri out" and "f*** Sarri-ball" as his side trailed to the Bluebirds in March.
Chelsea controversially came from behind to beat Neil Warnock's side 2-1, sparking a furious reaction from the Cardiff boss that landed him in trouble with the FA.
But it was Sarri who suffered most, reportedly deciding he had to leave after hearing the barracking from his own fans after Victor Camarasa had put the Bluebirds in front.
Cesar Azpilicueta's goal, which was clearly offside, and Ruben Loftus-Cheek's winner helped Chelsea secure a top four finish before they want on to lift the Europa League last month.
Sarri is on the brink of joining Juventus, with Frank Lampard firm favourite to replace him.
Warnock was fined £20,000 following the match after being found guilty of bringing the game into disrepute.
The FA took action after Warnock spoke out in TV and radio interviews following the Bluebirds' highly contentious 2-1 Premier League defeat to Chelsea on March 31.
Disciplinary chiefs were unhappy that an angry Warnock said Premier League referees were the worst in the world, although he was trying to point out in his interviews that VAR needed to come in to help officials.
They also didn't like Warnock's claims that smaller clubs like Cardiff were on the wrong end of decisions when playing the bigger teams, the FA insisting that was an accusation of referees being biased.
They also found against him over his clearly jovial remark about saying wife Sharon would have forgiven him for punching the referee on this occasion.
