The Brisbane Lions have stormed clear in a frenetic qualifying final shoot-out against Port Adelaide to move within two wins of breaking the club's 20-year AFL premiership drought.

Port threatened a Gabba upset when they rallied to lead in the second quarter and then surged again to trail by just 10 points in the third term.

But the hosts had the answers in a 19.9 (123) to 11.9 (75) win on Saturday night.

Cam Rayner (three goals) and Hugh McCluggage (26 disposals, nine clearances, four scoring assists, one goal) starred as Brisbane's usual weapon Lachie Neale was held to just a single first-quarter touch and finished with 19 in total.

Joe Daniher also kicked three of his five goals in a crucial third term run after Charlie Cameron had booted two in an instant in his 200th game.

"We were able to respond each time ... really good finals footy," coach Chris Fagan said.

"The footy world thinks if you tag Lachie Neale you beat Brisbane.

"Everyone notices when he's tagged successfully, but make no comment when he's tagged unsuccessfully.

"We don't need Lachie to dominate to win, I don't think. If that is the case then we can't go much further."

Port now host GWS in a knockout semi-final while Brisbane will host the winners of Melbourne-Carlton in a preliminary final at the Gabba - they haven't lost at the ground in 12 games this season - to earn a shot at their first flag since 2003.

The Power rued some errant kicking, the visitors scoring from 20 of their 48 forward entries but missing crucial set shots when the game was in the balance.

Usually reliable, Todd Marshall sprayed two of his from close-range that didn't even register. Ollie Lord was the unlikely source with a season-high four goals.

Willem Drew kept Neale under control but McCluggage stepped up, his poise and positioning ensuring Brisbane's offence flowed.

Connor Rozee played that role for the Power, often emerging out the front of stoppages to slice up the Lions' much-improved defence.

The 36,020 crowd were still singing Cameron's trademark Country Roads goal celebration song when the small forward raced onto another chance and kicked his second in a memorable third-quarter moment.

Marshall had the reply but McCluggage stayed calm, finding Daniher with another exquisite kick forward that prompted the Lions' decisive burst.

Earlier, Jason Horne-Francis had imposed himself on the contest with a series of barging runs and Port finally found their radar to boot three in quick time and snatch a two-point lead.

But Rayner popped up again to steal it back with his third goal, before McCluggage and Dayne Zorko took their chances in the closing stages of the half to rebuild a 16-point advantage.

Brisbane rookie Jaspa Fletcher (three goals) and teammate Callum Ah Chee were both rock solid when questions were asked.

Port coach Ken Hinkley substituted Darcy Byrne-Jones to inject veteran Travis Boak with seven minutes to play.

But then Trent McKenzie (ankle) and Dylan Williams (hamstring) hobbled off, with both now in severe doubt for next week's crunch clash.

"It plays a factor early in the game and Brisbane felt their power grow," Hinkley said of his side's poor kicking.

"We lacked some composure. When they overpowered us, they really overpowered us."