Furious Cardiff boss Neil Harris threatened his players with the axe after their 3-2 defeat at QPR.
Dom Ball's brilliant stoppage-time strike won the game for Rangers after Harris' side had fought back from 2-0 down.
QPR scored twice in a one-sided first half and could have been further ahead by the interval.
The Bluebirds' display in that opening 45 minutes angered Harris, who said: "The first half was the worst in the time I've been in charge.
"We were outfought, outrun and didn't defend our penalty area. We can't give teams head starts.
"I'm here to win games of football and be successful as Cardiff City manager and I expect my players to have the same mentality.
"We've got to bounce back. It's their jobs. It's what we're asking from them.
"It's their job to represent the club to the best of their ability and at the moment they're not doing it.
"I told the players in no uncertain terms where they're at fault and who is at fault. I've never been so angry after a game.
"I want to be successful and win games of football. If my players don't do that then they won't play."
After goals from Ilias Chair and Todd Kane put QPR in the driving seat, Joe Ralls pulled a goal back with a penalty early in the second half.
Ralls followed to equalise after his second spot-kick was saved by goalkeeper Seny Dieng, but Ball's brilliant goal gave Rangers the points.
Harris, whose team have won just two of their opening nine league games, said: "I will praise my players for the second half, when they were outstanding, bossed the game and looked a real threat going forward.
"People will say it (Ball's goal) was a great goal but it summed us up. When the ball goes forward it gets in behind us and that's not acceptable. I'm gutted."
QPR manager Mark Warburton was delighted with his team's first win in eight matches but admitted they still have much to learn.
Yoann Barbet's clumsy foul on Kieffer Moore resulted in the first penalty and Conor Masterson's handball led to the second.
"In the first half we played very well and looked a very good team," Warburton said.
"Energy was the key for us today. We played with real intensity and purpose. We got into good areas and were dangerous.
"But it's a 90-minute game. We've got to learn from the second half, where we shot ourselves in the foot by giving away ridiculous penalties.
"From a comfortable position – we should have been 3-0 up – it's 2-2 and they're putting balls in our box.
"When you're in the area against good forwards you've got to make good decisions, and on those occasions we didn't."
But Warburton insisted he has no doubt that his squad have enough quality to improve on their recent poor run.
"The players were angry because they felt we should have more points than we did," he said.
"They've worked hard in training and showed their quality today. I think we deserved to win.
"They're a good squad of players and when they play the game I know they're capable of playing, we're a good side."
