Greater Western Sydney involved in a match of the round? It seemed fanciful at the start of the season but the Giants' clash with Collingwood next Sunday has become one of huge importance with a top-four berth on the line after the expansion club's victory over Brisbane.

It says a lot about the Giants' progress this year that they are now marking wins, by five goals no less, with little fanfare, though beating the Lions is no cue to pop the champagne corks.

Nor will this game be worthy of keeping in the video library. As a spectacle it was every bit as dreary as Sydney's clash with Gold Coast – hardly the sort of advertisements the AFL would want in their developing markets.

But GWS coach Leon Cameron will not be worried about bells and whistles. Just bank the four points and move on.

The Giants have already surpassed their club record of six wins and, with a short injury list and friendly draw, have good reason to dream of a maiden September appearance.

Their win sets up a mouth-watering clash on Sunday against Collingwood at the Mecca of football, the MCG – a venue where the Giants rarely get an opportunity to play.

Cameron agreed the clash will be the biggest game in the club's short history.

"Probably, because of the build-up, where we sit on the ladder, we've never been in that position before," Cameron said.

"We're sitting 7-3 – it's been a great start to 2015 – but we know the fun's about to start."

A good team, which the Giants are aspiring to be, can still win when they are below their best. Not that the Giants needed to be at the top of their game to defeat a horribly undermanned Lions, missing close to half their best 22.

It still took the Giants until midway through the final quarter to put the result beyond doubt against a Lions side which showed plenty of application but lacked the class to make it count.

In a dour game where fluent play was rare, the class of Dylan Shiel and the grunt of Adam Treloar, Callan Ward and Shane Mumford eventually wore down the game Lions.

Mumford, with 51 hit-outs and eight bruising tackles, had a lively duel with Stefan Martin, who was also among his team's better players.

Under Justin Leppitsch, the Lions have been at their best playing a free-flowing style but, with so many out, resorted to a more defensive style, throwing large numbers behind the ball and trying to punish on the counter.

It worked, at least in the opening term, during which the Lions scored two goals from their first three entries inside 50 despite the game being played largely in the Giants' forward half.

Curiously, the Lions had more of the ball but were afforded little time and space by the Giants, who laid 37 tackles in the first quarter.

That suggested the Giants' effort was there but their entries inside 50 lacked precision as they resorted to long kicks to Jeremy Cameron and Cam McCarthy, who were outnumbered.

They were more prepared to run the ball in the second term and were rewarded with a run of three unanswered goals, including one to Dylan Shiel, who finished an outstanding passage of play in which the Giants ran in waves through the middle.

The Giants made their move in the third quarter with goals to Cameron, Lachie Whitfield and McCarthy, stretching the lead to 37 points.

But the Lions, led by imports Dayne Beams and Allen Christensen, kept coming, kicking the next three goals – all from Giants turnovers. And had Beams kicked truly at the 13-minute mark of the last term the deficit would have been just 16 points.

The game was over minutes later when McCarthy and Cameron goaled in quick succession.