LONDON • Two Dutchman put aside their antipathy to shake hands at kick-off.
However, Louis van Gaal and Ronald Koeman contested each other's views of the strength of Manchester United's defence in comments after the game ended.
Koeman felt his Southampton side exposed plenty of "weaknesses" in United's backline, notably during the opening half-hour on Sunday when they led 1-0.
However, he said his men lost their belief and organisation after conceding two soft goals either side of the interval.
United went on to win 3-2.
We saw the weaknesses of Manchester United, defensively. We showed at different moments our strengths but after 2-1, we lost belief and control.
RONALD KOEMAN Southampton manager
Van Gaal was forced to replace Matteo Darmian with Antonio Valencia at the interval. The Italy right-back could not cope with the pace and trickery of Dusan Tadic.
A clash of characters led to van Gaal and Koeman falling out at Ajax Amsterdam, and the United manager provided a stroppy response to Koeman's comments.
"This is also remarkable that he says that," van Gaal said.
"No, I am not concerned. I didn't see Tadic in the second half."
As the United manager left the press conference, he snapped: "Did Koeman say they were the better team? Write what Koeman said."
United had clean sheets in the opening three league games but have conceded in each of the past four games in all competitions.
They relied on David de Gea producing fantastic saves to deny an equaliser for Jose Fonte and Victor Wanyama.
"I thought from the bench, 'That is in' but David was still in the air," van Gaal said of the former effort.
There were positives at the attacking end.
Anthony Martial became the third player to score in both of his first two league appearances for United, joining Louis Saha and Federico Macheda.
The Red Devils strung 45 passes together in the build-up to Juan Mata's third goal.
No team have managed as high a number since Nacer Chadli rounded off a 48-pass move for Tottenham Hotspur against Queens Park Rangers in August a year ago.
"With that amount of passes, you control the game," van Gaal said.
"Gaps in the defence exist when you play a kind of positional game."
He added: "Today is confirmation of our philosophy."
Koeman's main gripe was his side's risky defending for a consecutive season against United.
Maya Yoshida's short back-pass gifted Martial his second goal.
The mistake was identical to how Fonte had given the Red Devils a goal last season.
"I will tell them tomorrow the same story. We lost by ourselves and not by our opponent," Koeman said. "We saw the weaknesses of Manchester United, defensively.
"We showed at different moments our strengths but after 2-1, we lost belief and control."
However, he had praise for Martial: "He is strong, fast, but if you have paid that kind of money, you can expect something."
THE TIMES, LONDON