Looking a completely different side to that which was embarrassed by Sydney last weekend, the Roos bolted home 21.5.131 to 12.10.82.
Geelong started the match well but completely dropped off in the second and third quarters, the ordinary display dramatically effecting the Cats' chances of a September appearance.
Both teams now stand at 9-10 with three rounds to play, with 12 wins the likely minimum for sneaking into eight.
The Roos run home - Adelaide, Richmond and Collingwood - looked likely to yield those three more victories than Geelong's schedule of Port Adelaide, Brisbane and Carlton.
Matthew Burton got the better of Steven King in ruck and consistently gave the Roos first use of the ball, with Adam Simpson, Brent Harvey, Shannon Grant and Shannon Motlop profiting with a swag of possessions.
While the Roos' tall forwards were below their best but still dominated with Jason McCartney shutting down Cats captain Ben Graham.
After Corey McKernan's match opening goal for the Roos, Geelong asserted itself with three unanswered goals, only for the momentum to swing again, with the Kangaroos getting two lots of two goals in a minute.
That was capped by the undeniable highlight of the night when beanpole Burton marked and from a flat-footed start executed four baulks around shorter opponents, leading to a David King goal.
The Kangaroos quarter-time lead of 19 points was doubled within ten minutes of the second term when McKernan goalled from a free-kick stemming from the reporting of Cameron Mooney for striking Jess Sinclair.
Geelong was still alive when 25 points down entering time-on of the second term, only for Motlop to kick a spectacular third goal to push the gap out to 43 points at halftime.
The third quarter was as tight and scrappy as the second term was free-flowing, with Geelong controlling play for large chunks but with too many of its attacks ending in points, while the Roos got three goals from three shots.
With the match in the Roos keeping, they failed to push for the percentage boost they badly needed, with Geelong getting some cheap final term goals.
Scoreboard:
KANGAROOS: 6.3, 14.4, 17.4, 21.5 (131)
GEELONG: 3.2, 7.3, 8.9, 12.10 (82)
Goals: Kangaroos: B Pickett 3 D King 3 S Motlop 3 S Grant 2 W Carey 2 S Rocca 2 B Harvey 2 T McKernan 2 B Rawlings T Makepeace. Geelong: B Graham 3 C Bizzell 2 C Enright 2 G Kilpatrick K Kingsley M White J Murphy M Scarlett.
Best: Kangaroos: A Simpson M Burton B Harvey S Grant J McCartney S Motlop. Geelong: P Riccardi B Sanderson S King.
Umpires: S McLaren M Ellis S McBurney.
Official crowd: 30,918 at Colonial Stadium.
