Veteran Steve Johnson showed he still has plenty to offer the Giants after his wily game-winning goal handed GWS their first win over Collingwood.

But the bruising three-point triumph against the Magpies came at a price with Stephen Coniglio re-injuring the ankle that cost him the opening six weeks of this season, and Aidan Corr and Sam Reid both suffering heavy concussions.

There were just 30 seconds left on the clock and one fit Giant on the bench when Johnson snuck out the back of a huge pack in front of the Giants goal to rove the football and send the 11,360 fans into raptures.

In a game of 15 lead changes, Collingwood looked to have honoured club great Lou Richards with a win just five days after he passed away aged 94 before Johnson chimed in.

"He's really working on his front-and-square and to get that with a minute to go was pleasing. I thought his last few games have been better and better, and he knows as well as I do and our footy club knows that he's building bit by bit," Giants coach Leon Cameron said of Johnson.

"He had an interrupted pre-season in terms of his constant touch and footy. We had to manage him with his knee, we had to manage him with his hand.

"I thought he found a way to produce some stuff that we know he can produce. To hit the scoreboard a couple of times and then to hit the one that put us in front is just testament that he just stays in the game, he's always thinking.

"He's probably done that a dozen times in his career in terms of real crunch moments and he played his role to perfection. It's pleasing that he's progressing in the right manner but he knows that he's got a lot of work to do."

Spearhead Jeremy Cameron booted six goals in the win while Josh Kelly produced a best-on-groud performance showing everyone once again why North Melbourne want to make him their $9 million man.

But it was the Giants' tackling pressure, and their undying will to win with the odds stacked against them, that built the foundation of their sixth victory of the season.

Corr lasted barely 20 seconds before he crashed sickeningly to the turf, and was helped from the field and never returned.

Rookie Reid joined him in the concussion ward midway through the second term while Coniglio limped from the ground at the start of the last quarter and could well be facing more frustration on the sideline.

The Magpies had their chances to win the game with Jordan De Goey missing everything when he had a flying shot at goal late on that would have put Collingwood out of reach, but it wasn't to be after an emotional week.

"We had chances that we should have iced in the last five minutes, but we weren't able to," Magpies coach Nathan Buckley said.

"Then there's just little things, little blues that we made, that gave the opposition the opportunity to steal it basically in the end. That's the way it goes. It was a flip of a coin in the last two or three minutes, whether we were going to be able to hold on, whether we would have the composure to possess the ball and shift it out of our back half and chew the clock up.

"In the end, it's not [GWS being] lucky - they forced it inside 50 four or five times in that last three minutes and eventually they scored. The message is, if you bring that effort you're going to win a lot of games of footy. Against a quality side, you've got to make sure you bring four quarters of footy."

This was arguably the bravest win in Giants history.

The three injuries suffered on Saturday compounded a growing toll that already includes Nick Haynes, Adam Kennedy, Ryan Griffen, Jacob Hopper and Brett Deledio.

At quarter-time Cameron's side was down by 26 points and being dominated in the ruck, but they turned it around.

"I'm not going to sit here and say it's not [satisfying], it's really pleasing," Cameron said.

"Sam Reid's a rookie, he comes back into our team. Daniel Lloyd's a rookie, plays his first game.

"It's not just on the basis of talent, this footy club. We know we've got some talent and a bit of that talent's sitting in the grandstands at the moment.

"It was pleasing that the guys just found a different way to win the game and that shows an enormous amount of character and we've got to continue on that.

"These sort of games are great to play in, as much as they're probably stressful for everyone to watch, they're an outstanding experience."

VOTES

Josh Kelly (GWS) 9

Jeremy Cameron (GWS) 8

Taylor Adams (Collingwood) 8

Dylan Shiel (GWS) 7

Tom Scully (GWS) 7