Louis Van Gaal blamed high emotions for his bizarre touchline spat with fourth official Mike Dean during Manchester United's 3-2 win over Arsenal at Old Trafford.
The Dutchman threw himself to the ground under Dean's nose in an attempt to illustrate his frustration at alleged diving by Gunners striker Alexis Sanchez.
With Gunners boss Arsene Wenger standing only yards away and trying hard not to react, Van Gaal continued to argue with Dean while he lay momentarily prostrate on the turf.
His colourful protest drew an enormous cheer from United fans and even a sporadic and rare outburst of "Louis Van Gaal's red and white army" from the Stretford End.
Van Gaal later admitted he had gone too far and revealed he had offered his apologies to the officials concerned.
Van Gaal said: "That was too emotional - it is not good for the referee and the linesman and the fourth official.
"It doesn't happen much normally - I have had a lot of criticism because I am sitting on my bench and now I am off my bench and I have lot of criticism because I'm doing that.
"I have apologised to the referee and the linesman and I hope everything is solved. I have to control my emotions and I have said that also to my players."
Wenger would only offer a wry smile when asked to venture an opinion on his opposite number's touchline antics.
"Nothing," Wenger replied. "You will have to ask him the question. I do not want to comment on that because (you will say) I'm a bitter loser - I am, in fact."
The game got away from his side in a three-minute first-half spell that saw Marcus Rashhford - the unknown quantity who stole the headlines with a double to help United get the better of Danish minnows Midtjylland in Thursday's Europa League battle - popped up with another timely brace.
Though former Old Trafford starlet Danny Welbeck replied, a deflected Ander Herrera effort restored the hosts' two-goal advantage ahead of Mesut Ozil reducing the arrears with what amounted to nothing more than a consolation.
"The player who was surprising for me, talent-wise was Rashford," added Wenger. "The timing and intelligence of his movement was great and he could be a very positive surprise for Manchester United."
The Frenchman argued that only a "quick and strong" response will save Arsenal's title ambitions.
Five points adrift of Leicester and three behind Tottenham, the Arsenal manager said the club's situation was far from irretrievable.
However, an immediate comeback was required both in Wednesday night's fixture at home to Swansea and what is likely to be the most intense North London derby in years at White Hart Lane on Saturday.
"Nobody knows how this defeat will impact on the title race," said Wenger. "We have dropped three important points and now we have to show we can fight on Wednesday night and not feel sorry for ourselves. The title is still possible but the answer will have to come quick and strong."
MANCHESTER UNITED: De Gea, Varela, Carrick, Blind, Rojo (Fosu-Mensah, 55 mins), Schneiderlin, Ander Herrera (Weir, 90 mins), Lingard, Mata, Depay, Rashford (Januzaj, 80 mins). Unused subs: Romero, McNair, Andreas Pereira, Riley.
ARSENAL: Cech, Bellerin, Gabriel, Koscielny, Monreal, Ramsey, Coquelin (Elneny, 70 mins), Walcott (Giroud, 63 mins), Ozil, Sanchez, Welbeck (Iwobi, 85 mins). Unused subs: Gibbs, Mertesacker, Ospina, Campbell.
Man of the match: Marcus Rashford
Match rating: 8/10
Referee: Craig Pawson (South Yorkshire)