A spot in the top eight was on the line for both teams and the SUNS, who had fallen 35 points behind in the third quarter, made a late charge when they cut the margin to just 15 points in the final term.
But the Dockers steadied through a clutch long-range goal to midfielder Jaeger O'Meara and claimed fifth spot on the ladder, winning 12.13 (85) to 10.5 (65) in a mature performance from the young group.
With the colours lowered against the Western Bulldogs last week, it was the Dockers' engine room that led an impressive response as Hayden Young, Andrew Brayshaw and Caleb Serong took control of the midfield and gave the team a 44-32 clearance advantage.
It became a key scoring source for Justin Longmuir's team, with that trio itself combining for five goals in a new side to the Dockers' midfield that could prove crucial in the run home if it can remain a weapon.
Young was outstanding with 24 disposals and three goals, with his piercing front half kicking a feature, while Brayshaw (32 and eight tackles) set the standard for midfield pressure after it was lacking against the Bulldogs.
Key forward Josh Treacy was immense in his 50th game, flying for contested grabs and kicking two important goals while also setting up others, with Sam Sturt (two) lifting as well.
There was a late concern for the Dockers as captain Alex Pearce left the ground with a left forearm injury that ended his day after he landed awkwardly in a contest.
For the SUNS, a potential spot in the top eight became 12th place as the ladder returned to parity following the mid-season bye period, with the visitors letting themselves down either side of half time when the Dockers kicked six goals to one.
The move of Sam Flanders (33 and four clearances) into the midfield inspired a late revival, but it was not enough, with Sam Day (three goals) also impressive in the absence of injured spearhead Ben King.
Longmuir's comments that Dockers had been "worried more about how many possessions they got" than other more important factors were still fresh on Sunday when the ball was bounced, and there was a watch on how his players would respond.
The early signs were concerning as Gold Coast burst from the blocks with two early goals, but the pressure, contest and team defence that Longmuir was looking for quickly emerged.
With that came their best offensive play as Young asserted himself and attacking kicks into the corridor became a feature through a second quarter run that saw them build a 24-point lead at the main break.
When Sean Darcy, playing his best game since returning from injury, hit the scoreboard early in the third quarter, the margin was 35 points and a comeback looked unlikely.
But the SUNS' midfielders, led by Touk Miller and Flanders, got on top at the stoppages and ensured the game was within reach when Brandon Ellis cut the margin to 15 points with six minutes to play.
It mattered little in the end, with O'Meara's set shot from 50m enough to settle the contest and ensure the SUNS road woes continued.
Flanders on the move again
The switch of Sam Flanders to half-back has been excellent for the SUNS this season, but he almost became the match-winning magnet when coach Damien Hardwick put him in the midfield late on Sunday. Flanders had nine disposals and four clearances in the last quarter and gave the SUNS some of the speed and dynamic movement they'd missed at stoppages. Whether Hardwick can afford to lose him from half-back, where he has been a star, is the question going forward.
FREMANTLE 2.3 6.7 10.12 12.13 (85)
GOLD COAST 2.0 3.2 6.2 10.5 (65)
GOALS
Fremantle: Young 3, Sturt 2, Treacy 2, Brayshaw, Darcy, Frederick, O'Meara, Serong
Gold Coast: Day 3, Lukosius 2, Swallow 2, Ellis, Graham, Long
BEST
Fremantle: Young, Brayshaw, Treacy, Serong, Darcy, Chapman
Gold Coast: Flanders, Powell, Day, Collins, Uwland, Rowell
INJURIES
Fremantle: Pearce (forearm)
Gold Coast: Nil
SUBSTITITES
Fremantle: Karl Worner (replaced Alex Pearce in the fourth quarter)
Gold Coast: Brandon Ellis (replaced Bailey Humphrey in the third quarter)
Crowd: 40,637 at Optus Stadium