Southampton manager Ronald Koeman accused Sheffield United counterpart Nigel Clough of showing a lack of respect after the Blades dumped his Barclays Premier League side out of the Capital One Cup on Tuesday night.
Koeman refused to shake hands with Clough at full-time after a spat in the wake of the Sky Bet League One side's 1-0 triumph, secured courtesy of Marc McNulty's 63rd-minute winner, which resulted in the hosts' first-team coach Chris Morgan being sent to the stands.
Southampton have now lost five games in a row and the nature of their performance in the cup quarter-final indicates the bubble of their stellar start to the season has firmly burst.
Koeman exchanged angry words with Clough and his coaching staff as tempers flared during the Blades’ goal celebrations.
The Dutchman explained his decision to snub the traditional post-match handshake by accusing his opposite number and his bench of disrespecting him and the fourth official.
“I shake hands with people who have respect for me and who have respect for the fourth official,” the Dutchman said.
“I think the behaviour of Sheffield United’s bench, I never saw that and that’s the reason I didn’t shake hands.”
The victory was United's second against a Premier League side this season and Clough was keen to play down the bust-up with Koeman and instead focus on his side's latest triumph against top-flight opposition.
“Not a lot is going to disappoint us tonight,” he said.
“He’s entitled to his opinion. I don’t think one word should be said on it, we should be talking about how we have just beaten a Premier League side.”
United’s victory was thoroughly deserved and their winning margin and Southampton’s humiliation would have been far greater had goalkeeper Fraser Forster not made a string of fine saves.
Clough added: “That’s the only slightly disappointing thing, we would have settled for a 1-0 I think, but we probably should have had a second goal tonight.
“It was a remarkable effort by the players.”
While rankled by what he thought was unacceptable behaviour by the opposition, Koeman had few complaints about the result.
“We didn’t bring our football and with the way they like to play it is difficult to win. That was the difference,” he added.
“I know that it is cup football and it is not about the level, they showed a fantastic spirit and that made it difficult.
“You know that it won’t be the first time a League One club beat a Premier League club and you know it won’t be the last.
“That’s football. But then you have to bring more quality on to the pitch and we didn’t.”