Up 14–13 at halftime, the Waratahs conceded 38 second half points to suffer a humiliating 14-51 Investec Super Rugby loss to the Chiefs in Wollongong on Friday.
Coach Rob Penney said the way the Waratahs let the score pile up had him very concerned.
"There's some pretty brutal terms that's been used to describe what that second-half looked like," Penney told Australian media.
The Chiefs were without seven All Blacks, including the dangerous Damian McKenzie who was on All Blacks rest leave, but that didn't hinder their effectiveness.
Having been competitive in the first half and scoring some spectacular tries of their own, the Waratahs wilted in the face of Chiefs pressure.
Six times the Waratahs dropped ball and turned it over.
"That happens through pressure, I guess, but it's not acceptable and it's embarrassing. It's tough on our supporters and people that believe in these boys and who want these boys to do well," he said.
When the Chiefs poured into the second half, with halfback Brad Weber, (pictured) crossing for a brace of tries scored within minutes of each other, the Waratahs fell off.
"I certainly think the Chiefs ratcheted up their intensity and we probably didn't match it and then we had a couple of errors back-to-back around our defence system. The boys made bad reads and Brad Weber, [a] world-class nine just ripped us.
"All of a sudden we're 14 points down after six minutes in that second half and we hadn't had the ability to fire a shot," Penney said.
He felt the Chiefs bullied the Waratahs off the ball three or four times at cleanouts.
"We just went in soft and high. Inexplicable. You can train that until the cows come home but if you don't want to put your body in a hard position, or a head in a hard spot, then you're not going to," he said.