The Cats displayed tremendous self-belief and application to outlast a gallant Brisbane, holding on in at times wet and windy conditions to record a significant 13.14 (92) to 9.11 (65) victory, their first against the Brisbane club post-merger.
The home side led by 12 points at the last change and saw that reduced to five points early in the last when Nigel Lappin slotted one through.
Instead of succumbing to the Lions' pressure, Geelong decided to write its own script instead, booting the last three goals, running away with the match and causing the 17,648 fans erupt with joy as the final siren sounded.
It moves Geelong to an 8-5 win-loss record, with the club now a legitimate chance to claim a position in the top four.
Ben Graham was outstanding up forward for the winners, with Cameron Ling strong again in the midfield and Brenton Sanderson providing excellent run off half-back.
But as has been the case all season, the Cats put in an even team performance with a host of contributions from second and third-year players that have taken the step up.
The Lions fall to 9-4.
The first half was a tight affair played in windy but sunny conditions, with the players unable to find time and space to show off their creativity and flair.
The visitors kicked the opening two goals of the match, but the Cats responded with the next two and trailed by only eight at the first break.
Brisbane started to flex its muscle in the second term, harassing the opposition ball-carriers with intense physical pressure. But to the home side's credit, it didn't buckle, showing the type of spirit and self-belief that has been the hallmark of its season to date.
As a result, the Lions went into the long break only three points ahead.
Given the conditions, goals were hard earned and no one was working harder than Lions centre half-forward Jonathan Brown, who was best on ground.
Brown kicked two opening half goals and was well on top in his personal battle with the in-form Tom Harley. He handled the footy beautifully all day, pulling down six marks and untroubled by the wind, rain or direct opponent. He finished the afternoon with four goals.
The early sunshine gave way to clouds and persistent rain in the last half and instead of lowering the standard of the contest, it did the opposite, with both teams scaling new heights.
The start of the third period saw Lions coach Leigh Matthews ring the changes in the hope of finding a combination capable of pulling off the sort of performance that blew away the Bombers the week before.
Daniel Bradshaw went back to mind Ben Graham, Jason Akermanis moved into the goal-square and Justin Leppitsch started the third term off the ground.
It didn't prove to be the winning formula, with the home side going ahead for the first time in the match courtesy of four behinds in six minutes and holding at 12-point edge at the final change courtesy of a five-goal-to-three third term.
If Brown was outstanding for Brisbane, veteran Graham was only marginally off being accorded the same level of praise. He 'saw off' Leppitsch in the first half with two goals and plenty of the footy and continued to lead hard and present for the footy against Bradshaw.
David Johnson did an excellent job blanketing the dangerous Jason Akermanis, with the 2001 Brownlow medallist restricted to only four touches in the opening term.
Cameron Ling moved onto Michael Voss in the second quarter after the Brisbane captain picked up 11 first-quarter possessions.
Brisbane coach Leigh Matthews felt his side wasn't really on its game, but paid tribute to Geelong's efforts in the conditions.
"They played better. They just seemed to be standing over the ball a bit better than us, running away from the contest a bit better than us," Matthews said.
"Last Saturday night we were exceptional, tonight we weren't good enough. That's within seven days. I think we're capable of better than we produced today but the opposition were too good for us on the day."
"We were in touch for most of the game but they gradually got clear. We really just didn't have much going for us most of the day despite the fact that we'd fronted early on."
After the break, the Cats take on West Coast in Perth and the Lions host Richmond.
Geelong: 2.3 5.4 10.10 13.14 (92)
Brisbane Lions: 3.5 5.7 8.10 9.11 (65)
Goals: Geelong: Graham, S Johnson, Kingsley, Mooney 2, Haynes, Corey, Ablett, Wojcinski, Ling 1
Brisbane Lions: Brown 4, Notting, Akermanis, Pike, McLaren, Lappin 1
Best: Geelong: Graham, Ling, Sanderson, D Johnson, Mooney, Wojcinski, Kelly, Scarlett
Brisbane Lions: Brown, Black, Voss, Lappin, Akermanis, McLaren
Injuries: Geelong: Sanderson (nose)
Brisbane Lions: Leppitsch (hamstring tightness), White (ankle), B Scott (quad)
Changes: Geelong Gardiner (corked thigh) replaced in the selected side by Haynes
Brisbane Lions: None
Reports: None
Umpires: McBurney, Schmitt, Jeffery
Crowd: 17,648 at Skilled Stadium
