The Roos led all night after setting the game alight in the opening term with six goals in the first 17 minutes, and looked to be home when Jack Ziebell goaled at the 14-minute mark to put North 32 points up.
But they had to dig deep – very deep – to escape with a 14.14 (98) to 13.14 (92) win that sets up a preliminary final meeting with the Sydney Swans at ANZ Stadium next Friday night.
Tom Hawkins was the Cat who almost stole victory for his team, kicking three consecutive goals in six minutes from the 16-minute mark of the final term to drag Geelong back into the contest.
The Cats piled on the last four goals of the match, getting to within six points at the 27-minute mark when Jimmy Bartel marked on the goal-line and converted from an acute angle.
The Roos frantically held on in the dying minutes, and ruckman Todd Goldstein was the hero, taking a game-saving pack mark 25m out from the Cats' goal with little more than 30 seconds remaining.
Even then, the Roos had to survive another scare when skipper Andrew Swallow was pinged for a deliberate out of bounds. Andrew Mackie pumped the Cats into attack one last time, but the final siren ended their charge – and their season.
North, who finished the home and away season in sixth spot, became the first team outside the top four to reach a preliminary final since Collingwood in 2007 – and just the third since the existing finals system was introduced in 2000 (Hawthorn in 2001 was the other).
The Roos set their win up in the first term, kicking seven of the game's first nine goals to lead by 30 points at the 27-minute mark of the first term. Apart from a few Geelong bursts, the Roos largely controlled the game until Hawkins' late flurry.
The Roos went into half time with a four-goal lead, but could not break the Cats despite stretching their lead to five goals on four occasions after the main break.
Goldstein was best on ground, taking full advantage of the Cats' undermanned ruck division by dominating Mark Blicavs and Josh Walker at ruck contests to give North's midfielders first use.
The Roos finished the game with 54 hit-outs, had 15 possessions and kicked one goal, but it was his game-saving mark that will live longest in North fans' memories.
Vice-captain Drew Petrie was outstanding for North, kicking 4.4 and setting the tone with his defensive pressure that earned him two free kicks for forward-50 tackles.
Nick Dal Santo was all class with 35 possessions and a clinical finish from a tight angle for a goal at the 12-minute mark of the third term.
Sam Gibson put on a trademark running clinic, exploiting his elite endurance to rack up an equal game-high 35 disposals, 24 of which came in a rampant first half.
Ben Cunnington and Levi Greenwood were also important in the midfield for the Roos, while Lindsay Thomas kick-started them with three goals in the game's opening eight minutes.
Geelong finished the home and away season in third and was the only top-five team North had not beaten this year entering September, with the Cats comfortably accounting for the Roos in rounds 10 (20 points) and 19 (32 points).
Hawkins finished with five goals for the match, after Nathan Grima had done a solid job on him for the first three quarters.
Josh Caddy was one of the Cats' best performers, giving Geelong a bustling presence up forward and in the midfield.
Geelong skipper Joel Selwood waged a one-man war against North at times in what was a spiteful clash, wearing strapping around his head after suffering a cut in a clash with Harvey in the second term.
Josh Walker also proved a handy foil for Hawkins, kicking a career-best three goals.
North's win helped coach Brad Scott close the gap in his head-to-head battle with twin brother and Cats coach Chris Scott, with the Roos now having won three of the teams' seven contests since Chris took over as coach in 2011.
The Roos will enter next Friday night's clash with Swans at ANZ Stadium on the back of six straight wins and armed with the confidence of having won its only clash with the Swans this year, by 43 points at the SCG in round four.
The Cats join West Coast (2007) and Port Adelaide (2001) as the only top-four teams to bow out of the finals in straight sets since 2000.
The Roos could regain Lachlan Hansen (hip) and Leigh Adams (concussion) for the preliminary final against the Swans.
GEELONG 5.1 5.6 8.9 13.14 (92)
NORTH MELBOURNE 7.1 9.6 12.9 14.14 (98)
GOALS
Geelong: Hawkins 5, Walker 3, Duncan, Caddy, Blicavs, Enright, Bartel
North Melbourne: Petrie 4, Thomas 3, Ziebell 2, Turner, Goldstein, Harvey, Black, Dal Santo
BEST
Geelong: Caddy, Hawkins, Selwood, Lonergan
North Melbourne: Dal Santo, Gibson, Goldstein, Petrie, Cunnington, McDonald
INJURIES
Geelong: Rivers (calf)
North Melbourne: McMillan (hamstring)
SUBSTITUTES
Geelong: Jackson Thurlow replaced by Lincoln McCarthy in the third quarter
North Melbourne: Jamie Macmillan replaced by Ryan Bastinac in the third quarter
Reports: Nil
Umpires: Nicholls, Meredith, Pannell
Official crowd: 65,963 at the MCG
