Derek McInnes admitted a "car crash" 20-minute spell killed Kilmarnock's chances of upsetting Celtic.
The Rugby Park boss despaired as a mistake gifted Celtic a sixth-minute opener before Ange Postecoglou's men added three more before the half-hour.
Fraser Murray's loose backpass was pinched by Kyogo Furhashi who staretd the rout before a Daizen Maeda netted and Matt O'Riley scored a brace.
For McInnes it was difficult to watch as his side crumbled under early pressure.
"The first goal was such sloppy one. It was a chance to be positive and the ball should have been in their box.
"The decision that was made to be negative in that situation, it’s not what we wanted. So we gifted Celtic and it was something similar to the start of the season where we played a part in the downfall with the cheapness of goals.
"Celtic are good enough to punish us. There was a 20-minute car crash watching it unfold.
"I don’t like making early changes but Doidge came off because we needed an extra midfielder and Fraser was really struggling after his mistake.
"I want players to show personality and courage to back themselves.
"Sometimes when you lose a goal your eagerness to make up for it means you start jumping out the slots and thinking that’s the best answer.
"But it makes it worse and Celtic played in between us. That 20 minute period was so difficult to watch.
"The changes helped us, we got a goal before half-time and I felt we were at least getting something against them. The extra midfielder helped us and we showed a pride in our performance and I thought we were the better team in second half. It was the team I wanted to see from the start."
The Kilmarnock boss was then left scratching his head in the second half as Oh Hyeon-gyu was cautioned for a high boot on Liam Donnelly.
Referee David Dickinson was quick to show the yellow after 71 minutes, but McInnes questioned the consistency in calls as he cited a red card for Kyle Vassell for a similar incident earlier in the season.
"He did [get away with red card]. I'm not looking for a red but likewise Kyle shouldn’t be a red at Easter Road. Where is consistency?
"You see the still and he has his boot in Donnelly’s face. It’s not a red card in same way I didn’t think Vassell was but VAR looking at same incident?
"It wouldn't have helped today but if it’s consistency, we’re not getting it from VAR. It was more dangerous than Kyle."
