Rafael Benitez has challenged Newcastle to rediscover their "character and passion" or face slipping to Premier League relegation with a whimper.
Comical defending and a limp, frozen performance from Newcastle gifted Southampton an easy 3-1 league win at St Mary's on Saturday.
Shane Long, Graziano Pelle and Victor Wanyama struck all too easily for Southampton, consigning Newcastle to a sixth defeat in a seven-match winless run.
Manager Benitez implored Newcastle's fuming fans to back his beleaguered side ahead of Saturday's critical home clash with Swansea, demanding a victory to keep the survival fight alive.
"Character and passion, and positive play - that's the very least of what is expected every game, for 90 minutes," said Benitez.
"But it is clear that that was very much lacking in the first half.
"That's not a situation that we can have away from home, so we have to make changes to how we'll play away from home.
"Before that we'll have to prepare for the next home game, and we just hope we can keep the fans behind us.
"It's very clear that we can say nothing to our fans.
"They come here to see the team fighting and winning and we didn't do that in the first half. So you have to understand their feelings.
"But we'll need support from the fans, we need them behind us to drive us on, to get a result against Swansea."
Hapless defender Steven Taylor was hauled off at half-time, so abysmal was the former Newcastle captain's performance on the south coast.
Taylor appeared racked with fear, crucially standing off Long for Southampton's opener, before full-back Daryl Janmaat's bungled attempt at an interception led directly to the hosts' second goal.
Taylor's replacement Jamal Lascelles later admitted Newcastle are lacking the hunger and fight required to beat the drop - challenging his team-mates to sharpen focus, and fast.
"It's not acceptable: as individuals we can't play like that and as a team or we will struggle," Lascelles told the BBC.
"The gaffer had a go at us at half-time. He said what we needed to do and we got a reaction with a goal back.
"But the only thing we can do now is put it behind us and focus on next week."
Southampton boss Ronald Koeman hailed his side for pulling off his risky plan of starting with a 4-2-4 formation - insisting he could yet reprise that ploy away at Everton on Saturday.
Koeman believes Saints can get away with pushing Dusan Tadic and Sadio Mane forward to partner Shane Long and Graziano Pelle in a heavily-offensive starting formation - but only if those players are then ready to tuck in and defend when required.
"We can certainly try it again," said Koeman of his aggressive tactics.
"It's really important that you don't give your opponent early feeling on the ball or chance to dominate.
"If this works they then have to run in bgehind you. That's what we like every game but it's also about the opponents, the strengths of the opponents.
"But of course we can try it again.
"A good start means a lot to everybody, about sharpness, spirit, belief and concentration.
"It's a very offensive way of playing, and you need really that responsibility of the strikers to keep the team compact, doing the job in defending and pressing.
"If not it's four defenders, two midfielders and four strikers, and I don't like that. So that's what I tried to explain to Sadio and to Dusan, play more inside, more midfield and you create space by yourself.
"And that was good in the first-half and we created a lot of problems for them."