Beaten 43-27, the Blues conceded five penalty goals, most of which Crusaders first five-eighths Richie Mo'unga, en route to a 28-point solo contribution, could have kicked in his sleep.
Blues coach Leon MacDonald felt the Blues showed by matching the Crusaders' four tries, they could break down their defence.
The difference was in conceding penalties that allowed the Crusaders to keep ramping up the pressure.
"Discipline is key to any of these games," he said.
"We talk a lot about controlling the game, and you generally do that when you've got the ball in your hand, and you're going forward and you get those calls.
"They hit us scrambling a bit on defence at times, were able to pull penalties and accumulate points every time they entered our half. That was disappointing, we were able to match them for tries, but, ultimately, our discipline was the difference," he said.
"We'd been good with discipline up to now. That's the first game we've got on the wrong side of the ledger around the discipline and that's disappointing for us.
"But, overall, there were a lot of areas in the game where we felt we were competing well," he said.
He felt some of the calls by referee Paul Williams had been tough on the Blues.
Achieving more competitive consistency with the Blues, during his first two seasons at the helm of the side, MacDonald's next step in the Blues' development should be eliminating the discipline issues too easily exposed in Sunday's outing.
"I think most of the stats would be pretty equal. The discipline wasn't. They were better than us.
"The scrums had good parity. We contested well around the tackle breakdown area. We were able to create space. There's a lot to be happy and excited about. But we've got to be better than we were because, ultimately, the scoreboard reflects a dominant victory to them.
"So there's enough for us to take away, to feel optimistic around how we're tracking, and how we're playing. If we were beat up in a lot of those areas, I'd feel differently, but I don't think we were," he said.
They had shown they were not too far away from the competition trendsetters, and when they had introduced their bench, they were able to demonstrate there was depth in the squad, but their contribution had probably been too late to influence the outcome, he said.