Sam Warburton admits Cardiff Blues must endure a painful review of Saturday's Challenge Cup defeat to Gloucester after letting themselves down with a bitterly disappointing 30 minutes.
Wales' Capital Region were hugely impressive for the majority of the quarter-final defeat and led 26-20 early in the second-half but it all came crashing down at Kingsholm.
Rampant Gloucester ran in four unanswered tries to render an impressive first-half Alex Cuthbert brace insufficient as the Blues crashed out of the competition.
"It's massively disappointing because we did really well in the first half, we were really physical and took some good tries," Warburton told the Cardiff Blues.
"I really don't know what happened, there were times where we messed up at scrum, lost a lot of territory and then made another mistake and when you make three mistakes on a bounce it often leads to three points or a try and that's what happened.
"There were too many times when we made too many mistakes one after another and that gave Gloucester way too much momentum and they scored too many unanswered points.
"There were a couple of first phase tries, one off the lineout, where we were blocked or there was a missed tackle and in fairness to Gloucester when they had line-breaks they deserved them. They were clinical.
"We have to get back into training and really look at that last 30 minutes because the first 50 was pretty good against a great Gloucester team and we then let ourselves down."
The Blues return to PRO12 action this weekend with another daunting trip, to face Ulster at the Kingspan Stadium.
With hope of European silverware dashed, the focus now remains solely on securing a play-off place to have a chance of qualifying for the Champions Cup.
But to have a chance, Warburton insists his side must begin to perform for 80 minutes.
He added: "We play well in patches but the top teams play consistently well over the majority of 80 minutes and we weren't that. We weren't good enough."