THE BRISBANE Lions' 83-point loss to Port Adelaide was the team's poorest effort of the season, according to coach Chris Fagan.

Following five competitive matches to start his coaching tenure, Fagan conceded Saturday night's thumping took him by surprise.

The Lions had more disposals (400-386) and clearances (37-34) than Port, but were outplayed from the opening minutes and gave little more than a whimper all night.

Asked what happened to the defensive intensity that had characterised the Lions' start to the season, Fagan was blunt.

"That's our poorest effort of the season in that regards," he said.

"I'm not sure why it happened because the one thing we have brought to all of our games until this point in time has been effort, tackle pressure, run, but tonight, particularly in the first half it was down.

"There was some semblance of an effort after half-time to fix it up, but still not to the level that we require."

Fagan said the Lions overused handballs, inviting trouble from a Power team that was in the mood to punish mistakes.

Despite having so many disposals, the Lions were terribly indirect, losing the inside 50 count 67-38 and gaining 1500m less than their opponents.

Fagan said following last week's strong showing against the Western Bulldogs, he expected the same against the Power.

"We've been terribly honest with our performances until tonight, but tonight the more senior players, who have been absolutely fantastic for five weeks, probably had a quieter night than they've had," he said.

"Some of the younger boys looked on the tired side and we played a Port side that was on from the get-go and put us under enormous pressure, played a fantastic style of footy and pretty much put us to the sword.

"It felt like we were off in all elements of our game, and sometimes when that starts to happen to you, players on the field can internalise and structures fall apart.

"We'll do what we've always done … go away and take what we can learn, front up next week and be better."