The SUNS led by just two points at half-time, but five goals to one in the third quarter put the game beyond reach.
The SUNS won 0.12.8 (80) to 0.8.7 (55).
After a scrappy first half on a lush Southport surface, the injection of Zac Smith into the ruck and move of Charlie Dixon forward sparked the SUNS.
Dixon started the damage with two contested marks – a juggling one-hander and a leaping grab from the side of the pack – that resulted in two goals.
After sitting on the bench for the first half, Smith then drifted forward and took a contested mark of his own and converted from a tight angle to extend the lead to 19 points.
His impact was profound both in the ruck and around the ground and should almost guarantee his place for the SUNS' season opener against St Kilda in two weeks.
Steven May also took a pack mark in the forward 50 and Sam Day laid on an easy goal for Daniel Gorringe before being moved to defence where he looked right at home.
Gold Coast coach Guy McKenna said it was pleasing to see the big guys take their marks.
"We need to cut them some slack but unfortunately given our unique list, we can't wait for them, but certainly the signs we saw today were very pleasing," he said.
"It certainly makes it a tough decision (for round one), but that's good. We were scratching our head coming into this game who was our number one and number two ruck, but now we've got some really tough decisions to make which is fantastic."
After a promising first quarter where they led by nine points, the Demons stalled in the Southport sun for the following two terms.
They were without tall timber Mitch Clark, Chris Dawes and James Frawley, which made a difference.
Jack Watts was arguably the best player on the ground (25 disposals), roving around half-back and looking a class above his teammates.
Captain Jack Grimes tried hard all day and won plenty of the ball (22 disposals), while young forward Jesse Hogan looked sharp in his limited opportunities.
Aaron Hall kicked three goals for the winners, while captain Gary Ablett (24 touches and two goals) was his usual industrious self.
GOLD COAST SUNS 1.0 4.5 9.6 12.8 (80)
MELBOURNE 2.3 4.3 5.5 8.7 (55)
GOALS
Gold Coast SUNS: Hall 3, Ablett 2, Dixon 2, Harbrow, Lonergan, Smith, Gorringe, Hutchins
Melbourne: Sellar 3, Terlich, Jamar, Pederson, M.Jones, Hogan
BEST
Gold Coast SUNS: Ablett, Hall, Harbrow, Dixon, Prestia, Thompson
Melbourne: Watts, Grimes, Jamar, Terlich, Sellar
INJURIES
Gold Coast SUNS: Lonergan (wrist)
Melbourne: nil
Reports: Nil
