The Demons sit seventh on the ladder with two wins and a draw from four matches, but Grimes says they're yet to put in a complete four-quarter performance.
"You take a 90-point win any day of the week, and I suppose the last few years we've probably been on the receiving end of a few of those losses, so it's definitely a big confidence booster, especially because we finished off the game so well," Grimes said on Monday.
"The last couple of weeks we've had a couple of wins but I still don't think we've put that four-quarter effort together yet.
"Even yesterday you could see we started a bit slow again, let them into the game and they kicked a couple of early goals, and we got beaten in the third quarter."
Gold Coast won a quarter for the first time in its history during yesterday's clash, kicking 4.6 to Melbourne's 4.5 in the third term.
Although not as damaging because they were able kick away again late in the game, the third quarter drop-off was a similar scenario to the Demons' round two loss when Hawthorn piled on eight goals to put the game out of reach.
"It showed when we played Hawthorn. We dropped off for a quarter and in that quarter we lost the game, pretty much," Grimes said.
"We know we can't afford to do that against the top teams, and we've got a few big games coming up."
The 21 year-old paid credit to the young Suns for their brief fightback, singling out No.1 draft pick David Swallow for particular praise.
"Going into half-time we probably felt a bit comfortable as to where we were at," Grimes said.
"We came out in the third quarter and probably dropped the intensity a little bit, and to Gold Coast's credit they really took advantage and got themselves back in the game.
"They've definitely got some talent there. I thought Swallow was terrific.
"They've got a lot of young guys that are really stepping up and it'll come together and they shouldn't be too far away."
The Demons have the bye in round five before travelling to Perth to take on West Coast on Thursday week.
Grimes said maintaining intensity for a full match would be crucial if the side is to overcome John Worsfold's much-improved Eagles.
"West Coast is in top form as well and they'll be a tough ask over there, so that (keeping intensity up for a full game) will be our aim going into next week," he said.
