Brisbane has moved level on points with Melbourne and Port Adelaide and set up a thrilling race for a top-two finish after hanging on for a three-point win against Fremantle at Optus Stadium.
The Lions trailed early in a rollicking final quarter before their key forwards took charge to kick three crucial goals and deliver a vital four points on the road, winning 11.11 (77) to 11.8 (74).
The Freo Dockers, who were playing to keep their own slim finals hopes alive mathematically, looked potential winners when Sam Sturt kicked a clutch 50m set shot from the boundary.
But small forward Charlie Cameron set up Eric Hipwood for the crucial late goal that gave the Lions an eight-point edge at the 26-minute mark.
Michael Frederick made them play right to the siren when he kicked a sublimely skilled banana goal on the boundary with one minute to play, but the Lions were good enough to soak up their opponents late charges and control the ball when they needed.
The win leaves coach Chris Fagan's men in third place, ahead of the Power on percentage and just 1.1 per cent behind the second-placed Demons as the clubs jockey for a vital top-two place in the final three rounds.
It was a gutsy win from the Lions, who were forced to grind through periods of the game when their midfield opponents were well on top but found a way to never let the scoreboard get out of control.
Star midfielder Lachie Neale typified his team. The Brownlow medallist was beaten early by big-bodied Freo Docker Hayden Young but stayed in the game and finished with a team-high eight clearances and 25 disposals.
Midfielder Hugh McCluggage (22 and five inside 50s), and the versatile Cam Rayner (19 and 12 marks) were excellent, while Cameron (two goals and six marks) stood up in important moments.
Freo stood up to the fierce Brisbane pressure to win just their third opening quarter of the season, having previously edged only Essendon and Hawthorn in what has been one of the repeated concerns of their year.
They did it through a midfield unit that was led by Jackson in the ruck and Young at ground level, attacking the contested ball and linking up well out of congestion to take a four-point lead at the first break.
The Lions steadied at the start of the start of the second as the well-held Josh Dunkley and Neale worked into the game, with back-to-back goals for Jack Gunston and Joe Daniher giving them some momentum.
Freo responded again, however, and enjoyed a four-goal run either side of half-time as Jackson asserted his authority on the match from the ruck, in attack, and even drifting back to take intercept marks and spoil on the goal line.
The third quarter was a shootout, with Fremantle getting out to a game-high 15-point lead early before the Lions responded with three on the trot, including an excellent running effort from Jarrod Berry from 50m.
Charlie Cameron also started to get on top in a tight match-up with Jordan Clark, taking a contested mark and then using smart bodywork to draw a free kick for his two goals.
A 55m running shot from Jackson as the siren sounded levelled scores at the final break before a thrilling final quarter that went down to the wire.
FREMANTLE 2.2 5.4 8.8 11.8 (74)
BRISBANE 1.4 3.5 8.8 11.11 (77)
GOALS
Fremantle: Sturt 3, Frederick 2, Schultz 2, Amiss, Corbett, Jackson, Treacy
Brisbane: Cameron 2, Daniher 2, Gunston 2, Ah Chee, Berry, Hipwood, McCarthy, McCluggage
BEST
Fremantle: Serong, Jackson, Young, Brayshaw, Sturt
Brisbane: Neale, McCluggage, Cameron, Rayner, McCarthy
INJURIES
Fremantle: Hughes (leg)
Brisbane: Nil
SUBSTITUTES
Fremantle: Matthew Johnson (replaced Ethan Hughes at three-quarter time)
Brisbane: Deven Robertson (replaced Jaspa Fletcher in the fourth quarter)
Crowd: 37,845 at Optus Stadium
