Michael Maguire has blasted his Wests Tigers and accused them of playing for just 10 minutes after they were shocked 26-20 by the Warriors.
Determined to turn things around at the club, Maguire was seen kicking a chair over at half time and then giving the players a bake after the siren.
After claiming an 8-0 lead early, the Tigers defence wilted as they blew a chance to move back into the top eight ahead of arguably the toughest run home of any team.
"I keep talking about an 80-minute game," Maguire said.
"We played for about 10 minutes. And then we weren't putting our body in front of them."
It marked the second time this season the Tigers have dropped a game to a lower-ranked team, with this performance easily their worst since the round-three loss to Gold Coast.
"I'm not happy," Maguire said. "That's not a Wests Tigers performance any more, that's not acceptable around the club.
"It's really disappointing to be honest. If you don't turn up prepared with the right mindset to any game in the NRL that's what happens."
For the Warriors, a memorable win came as a triumph for the club's resilience.
Just days after waving goodbye to four players who left the country to return home to their families, they fought back and held firm through a nervy final five minutes.
Centre Peta Hiku scored a double while fullback Roger Tuivasa-Sheck was again one of the New Zealand side's best despite some early errors.
Tohu Harris and Jack Hetherington were also immense up front, with the former scoring a crucial second-half try at the SCG.
The Warriors have now been in Australia for almost three months but they showed plenty of spirit on Friday night after conceding two early tries.
"It could have gone either way," coach Todd Payten said.
"Really happy, proud of our organisation and our group. It's well documented everything we are going through at the moment.
"The players in the group are starting to hold themselves accountable. We've had four guys go, so everyone is here ready to dig in."
Hiku changed the match early in the second half when he first pushed his way through three Tigers to level the scores, before taking on Adam Doueihi and narrowly staying in to take the lead.
And when Harris made the most of a Tommy Talau error at the back, it was 26-14 and the game was all but over.
Doueihi crossed with six minutes to go to give the Tigers some hope, but they blew a last-minute chance when Chris Lawrence put a pass into touch.
It was a far cry from the Tigers who roared into the game and opened the scoring when Moses Mbye ran onto a magical Luciano Leilua offload to touch down inside five minutes.
And it looked as if they were set to enter party mode when David Nofoaluma scored his 11th try of the season with a tip-toeing effort from an Doueihi cut-out ball.
But the danger signs were there when Karl Lawton split the Tigers' line open from dummy-half shortly after to put the Warriors back in the match.