What's been an incredible roller-coaster of an AFL season kept going as the fight for a place in the top eight keeps fans enthralled.

Fans of Collingwood, Carlton and Melbourne will disagree, but the weekend's matches again showed what a funny old game football can be.

Just about all that could go wrong did go wrong before and during Collingwood's clash with the Brisbane Lions at the MCG.

The late withdrawal of classy small forward Jamie Elliott, injury to captain Scott Pendlebury in the pre-game warm-up, and then injuries to more stars in the contest cruelled the Pies chances against the rampant Lions.

A black cat invaded Adelaide Oval, but Collingwood fans must have thought at least a dozen black cats had run onto the MCG.

Being smashed by the Lions, who had been belted by more than 100 points the previous round, did little to appease the mood of the thousands of Magpie fans around the country.

Mid-season and the Pies were eyeing a top-four berth and another serious tilt at a premiership.

Two rounds to go and Collingwood's hopes of figuring in September are all but gone.

The Pies free-fall shows just how fickle form and on-field fortunes can be.

Carlton fans were again riled by an umpire's controversial decision late in their game with Geelong.

It was the second time this season that the Blues had been stung by a call that cost them a chance to win the game, or at least on Friday night, draw with the Cats.

The result of a match cannot be determined by just one decision, but the call by the non-officiating umpire to pay a free in a marking contest to Geelong's Allen Christensen was baffling.

Christensen's goal was to be the match-winner.

Melbourne fans could not blame the umpires for their team's insipid performance against Greater Western Sydney.

Skill errors, poor decisions and a lack of desire for the contest had Demons fans well and truly fired up by match end.

Melbourne's latest performance was in stark contrast to the fight the team had put together for a lot of this season.

Fans of Richmond, Essendon, Adelaide, West Coast and Gold Coast still have plenty to look forward to.

Hard-fought wins by the Tigers and Essendon have kept hopes of figuring in September alive.

How Essendon could play so poorly in the first half and then turn it on in the next had many Bombers fans stumped.

The Bombers cannot afford to be so lax in their next two hit-outs against Gold Coast and Carlton.

There's 18 contests to go in the home-and-away series and so much drama to be played out.