After losses to St Kilda (17 points) and West Coast (93), and hamstrung by key injuries and absences – the forward line is missing Mitch Clark, Chris Dawes and Jesse Hogan – Roos had promised to shake things up.

"We haven't had any forward-of-the-ball structure with the key talls out, so we had to do something different today with [Lynden] Dunn and [James] Frawley," Roos said.

"Obviously we lost the game, but defensively we had nine or 10 goals scored against us [compared to 18 last week], so we weren't too bad.

"Forward of the ball at least we had some shape and some targets to go to. From that point of view, we did look a lot better. Guys went forward with a lot more confidence at times."

Roos said he wasn't sure if the team had made any progress. "It's hard to tell really. As a group, we've just got to continue to get better and understand what is AFL footy. We have to make sure we lift those standards and move forward in that direction.

"Is it a step forward or step back? It's hard to tell. I don't like losing any week."

What the match lacked in skills and execution in challenging, drizzly conditions, it atoned with a result that remained in doubt until the Giants repeated the type of big last-quarter push that gave them an unlikely victory against the Swans in round one.

Their five-goals-to-one response to the Demons' third-quarter revival, in which the Demons briefly led, was punctuated by two goals to young star Josh Kelly, one to Shane Mumford – who was exceptional for the Giants in the ruck – and final nails in Melbourne's coffin from Devon Smith and Stephen Coniglio.

Roos – on his first trip back to Sydney as a coach – pointed to the tackle and hitout counts as decisive. "They tackled really well. They didn't give us time or space," he said. "That's what AFL footy is. You've got to tackle. We tackled 40 or 45 times less.

"As a group, we've got to continue to get better. We've got to understand 'What is AFL footy? What does it demand?' That's part of the process. We've got to keep moving forward."

Giants coach Leon Cameron said: "The good thing about the game is that, when Melbourne came at us at the back end of the third quarter, for them to get in front and for us to respond, I thought was fantastic and helped us in playing a dominant last quarter.

"It's fantastic that our fitness staff, our sports science area, has done a great job over our pre-season.

"It gives you great confidence that when you come to that three-quarter-time siren, we break and then know we've got the run in the legs to last the last quarter."

The Giants had more than twice as many hitouts, led by Mumford's personal record 60 taps.