Fremantle are all that stands between Brisbane and a three-peat after the dual reigning premiers fought off Hawthorn for a nine-point preliminary final victory at the MCG.

But while the game will go down as one of the great finals, a controversial holding-the-ball free kick in the last 30 seconds marred the ending and handed the Lions a fourth trip to the decider in as many years 20.11 (131) to 19.8 (122).

While the Dockers hunt a maiden premiership cup after taking down the Swans at the SCG on Friday night, the Lions will be out to solidify their status as the dominant team of the decade as they hunt their second three peat in club history.

Saturday’s victory didn’t come without a massive scare; star midfielder Lachie Neale was knocked flat at the opening bounce with a big bump before recovering, while the Lions gave up a 20-point lead in the last term to be on the precipice of elimination.

A six-goal run, half of those kicked by Kai Lohmann, put the Lions 20 points ahead at the final change of ends before another to start the last had one foot in the decider.

But Sam Mitchell’s men were far from out of the fight, piling on five goals in a row as Nick Watson’s sixth put them back in front.

The two sides exchanged the lead twice more before Jarmen Impey was called for holding the ball 20 metres out from his defensive end for not attempting to get rid of the ball despite having one arm free.

Hugh McCluggage was cool as ice, slotting the goal to get ahead before Lohmann slotted a sealer after the siren.

There were ugly scenes after the siren with fans seen throwing items at the umpires as they departed the field with at least one spectator pointed out to security guards.

The Lions won’t hold fear for the Dockers, who knocked off the reigning premiers on their home deck in round 12.

However, the vast majority of Fremantle’s group have never experienced grand final day, while almost all of the Lions have.

Will Ashcroft was inspirational in Brisbane’s preliminary final triumph, collecting 28 disposals and eight clearances while McCluggage was also influential in the clinches.

There were nine lead changes in the game - four alone late in the final term.

Among many highlights, Hawks key forward Mitch Lewis took a soaring mark and kicked a goal to put them back in front with only a couple of minutes left.

Tom Barrass and James Sicily then took two massive defensive marks, but the Lions went forward again and the crucial free was paid against Impey.