Unai Emery shoved Youri Tielemans in an extraordinary touchline show of aggression towards his own player after subbing him off.
The Aston Villa manager was caught on camera getting up close and personal with the Belgian midfielder, who he brought off in the 89th minute in the 1-0 Europa League win over Fenerbahce.
Tielemans gave a brief embrace to his replacement George Hemmings as he came off and attempted to put his hand on his manager's waist.
But Emery was already furious and had no interest in shaking the player's hand.
Instead he waved his arms theatrically and screamed in Tielemans' face before shoving him towards the dugout.
Fortunately the situation did not escalate and Tielemans opted not to go back and physically confront his manager after the bizarre and embarrassing altercation.
It remains to be seen what in particular Emery was so annoyed about that cause him to lose his rag.
When asked about it in the post-match interview, Emery simply said: 'He is my son, he is my son.'
Some theorised that he was wound up by Tielemans picking up a yellow card, others thought he was worried about the Belgian getting another caution for coming off slowly and some posited the opposite, that he should have wasted more time by slowing down.
Villa were 1-0 up at the time through Jadon Sancho's 25th-minute goal and his goal proved to be decisive, with the visitors holding on for all three points.
Tielemans was on a yellow card at the time he was subbed and appeared emotionless when confronted by his manager.
Footage of the incident was widely shared online and fans could hardly believe what they were seeing.
One wrote: 'Why did Emery just lose his s*** with Tielemans?
Another posted: 'Emery is fuming with Tielemans.' And a third put: 'What was Emery doing to Tielemans there???''
The 28-year-old was part of a strong line-up including Morgan Rogers, Ollie Watkins and Emiliano Buendia for the tough game in Turkey.
Despite the flashpoint on the touchline, Villa were able to get the job done and earn a victory that takes them to 18 points in the Europa League table.
It has been a stellar European campaign for Emery's men so far with six wins and just one defeat.
The win on Thursday night secured them a place in the last-16 and the Premier League side will be among the favourites to win the final in May.