Ralph Hasenhuttl accused his Southampton players of giving up after they wilted at Elland Road.
Southampton conceded three second-half goals to sink to their seventh defeat from their last eight league games and Hasenhuttl was not happy with their attitude.
“It was a deserved win for Leeds because they had more energy in the second half,” said the Saints boss.
“We gave up in the second half and that is not what I like. We were nasty in the first half, but we were a nice opponent in the second half and gave them the three points easily.
“In the second half we were stretched, they showed our weakness immediately.”
Hasenhuttl refused to blame referee Andre Marriner for overturning his decision to award Southampton a penalty and disallowing a goal because they took a free-kick before he blew his whistle.
“Our disallowed goal was one second played too early and it’s tough to take, but let’s not discuss the referee,” he said. “We deserved to lose today.”
Stuart Dallas pulled up his shirt to show a tribute to Kalvin Phillips’ Granny Val, who died a few days ago, and Marcelo Bielsa said they all feel her loss.
“When we got promoted, Kalvin’s granny became known to the public and we all came to care for her,” said the Leeds boss.
“Kalvin had many reasons why he loved her do much and she was charismatic and an attractive person.
“We regret deeply that she is no longer with us and the loss to Kalvin and his family.”
Leeds are next in action when they take on Aston Villa on Saturday, while the Saints travel to Everton on Monday March 1.
