Jose Mourinho accused Antonio Conte of attempting to humiliate him during Manchester United's 4-0 defeat at Chelsea, with the Old Trafford manager criticising the Italian for playing to the crowd in the final moments of his miserable return to Stamford Bridge.
Mourinho, sacked by Chelsea last December, was overheard telling Conte at the end of the game, "You can do it at 1-0, but not at 4-0", after his successor urged the home supporters to raise the noise levels in the closing stages.
The United manager refused to divulge the content of his touchline row with Conte, claiming: "What is between me and Antonio is for us. I spoke to Conte, not to you."
But former Juventus and Italy coach Conte defended his actions and insisted he had no intention of "humiliating" Mourinho.
"I only told the fans to applaud the team because the team deserved it," Conte said. "There has always been respect for all, and naturally for Manchester United.
"Nothing happened. I did something absolutely normal. I didn't do anything to humiliate Mourinho."
Whether Conte set out to humiliate his opposite number or not, the Italian's players did the job for him by inflicting Mourinho's heaviest ever defeat in English football.
After taking the lead through Pedro on 29 seconds, Chelsea proceeded to secure an emphatic victory, but Mourinho claimed his team's performance was not as bad as the scoreline suggests.
"It started badly after a few seconds," Mourinho said.
"You come with a strategy, so you cannot concede a goal in the way we did.
"We were coming to have an offensive approach, we wanted to create chances. We showed that after the 1-0.
"The second and the third were counter-attack goals. If we score a goal like we almost did for the 2-1 the game would be different.
"It is one of those days when you give the advantage to opponents by doing nothing."
Mourinho accepted, however, that individual errors by the likes of Daley Blind, Chris Smalling and Paul Pogba proved decisive in United's defeat.
"We made incredible defensive mistakes, individual mistakes and you pay for that," he said. "In terms of points, we got zero points, we lose three points.
"We are six points from the top, three (five) from the top four, we now need to win matches. We need to win our matches now, which are not easy.
"We need to win to close that gap, after these last three matches, we made two out of nine, we now need points.
"But the team played well, if we can delete the defensive mistakes we made. Thibaut Courtois had more work than De Gea, their defenders had more work than my defenders."
Mourinho, meanwhile, insisted he was unmoved by the muted reception from the Chelsea supporters on his first game back at Stamford Bridge.
"I didn't feel it," Mourinho said. "I was in the game. For sure it was not negative, it had no reason to be. What would they have against me, or me against them? Nothing. Everything was like it should be. Calm.
"I was not expecting anything different here. The crowd behaved in a normal way and I didn't feel it different to any other big matches."
United face Manchester City at Old Trafford in the League Cup on Wednesday with Mourinho admitting that defender Eric Bailly will miss the game with a potentially serious knee injury.
"He is injured and I'm afraid he's badly injured," Mourinho said. "In his knee, in the ligament area. He feels that it is really bad."
Chelsea now sit in fourth, just one point off leaders Man City.
"This game was very important for our ambition," Conte said. "After two defeats against two great teams like Liverpool and Arsenal, it was very important to have a good answer and to win against a very strong team.
"After this type of win, it usually increases confidence.