The visitors won 15.23 (113) to 15.10 (100) but not before the Lions reduced a 26-point lead to just six points in an exhilarating final quarter.
Not only did the Lions lose the match, but they also lost stars Jared Brennan (ankle) and Josh Drummond (knee) to what looked like serious injuries.
Both hobbled off during the third quarter and did not return.
The Lions lost Joel Patfull before the match and were also without Matt Maguire (suspended), Daniel Merrett and Mitch Clark (injured).
But Fremantle deserved their win and only their poor kicking kept the Lions in the match for much of the night.
Captain Matthew Pavlich was a guilty party, finishing with 3.4, but he was a star for his team whether up forward or in the middle.
Stephen Hill was all class in the middle, while Chris Tarrant and Luke McPharlin wore respective opponents Jonathan Brown (one goal) and Brendan Fevola (three) like gloves.
Freo led at every change and their slick ball movement was a feature in the first three terms before the Lions made a final-term surge.
Freo’s win keeps its top four hopes well and truly alive ahead of coming matches against Collingwood and the Swans.
Brisbane Lions 5.2 6.4 10.7 15.10 (100)
Fremantle 5.5 9.9 12.15 15.23 (113)
GOALS
Brisbane Lions: Fevola 3, Banfield 2, Black 2, Brown, Drummond, McGrath, Rich, Rischitelli, Rockliff, Sherman, Stiller.
Fremantle: Pavlich 3, Johnson 2, Haselby 2, Ballantyne 2, Barlow, Fyfe, Mayne, Morabito, Palmer, Sandilands.
BEST
Brisbane Lions: Black, Rischitelli, McGrath, Staker, Power, Sherman
Fremantle: Hill, Mundy, Tarrant, McPharlin, Barlow, Pavlich, Ballantyne
INJURIES
Brisbane Lions: Patfull, Drummond (knee), Brennan (ankle)
Fremantle: Nil
Reports: Nil
Umpires: Nicholls, McInerney, Mollison
Official crowd: 27,739 at the Gabba
The views in this article are those of the author and not necessarily those of the clubs or the AFL.