AFTER such a promising pre-season, Brisbane Lions coach Justin Leppitsch was dumbfounded by the poor first three quarters against Collingwood on Saturday night.

Collingwood led by as many as 53 points and could have pushed the lead even further, before the Lions banged on the final seven goals to get within 12 points by the finish.

Despite the comeback, the Lions were smashed around the contest for much of the night, showing none of the combativeness and enthusiasm that had typified their unbeaten NAB Challenge campaign.

Leppitsch was at a total loss to explain why.

"It's extremely frustrating … three quarters of watching us get completely obliterated in contested possession, effort and tackling and all those key indicators, to somehow turn it around," Leppitsch said.

"Who knows? I'd love to get to the bottom of it because we haven't shown that yet, we've been pretty competitive in the pre-season.

"That's probably as poor as we've gone.

"I guess the positive is a game like that last year, we'd have lost by 100 points given equal circumstances."

The Lions had 14 more contested possessions in a dominant final term, yet still lost the overall count 165-152.

Collingwood also won the inside 50s (61-49) and tackles (77-68).

The much-vaunted Lions midfield was outplayed most of the way, but Leppitsch said he was also disappointed with the pressure in the forward half.

"Maybe it's round one, a big occasion, we haven't been in this situation very often," he said.

"In these moments you've got to be composed, take what's coming and deliver, and we didn't do that. We failed for most of the game. It's good lessons."