The Dockers claimed their sixth straight victory, and their fifth consecutive derby, winning 13.10 (88) to 11.15 (81) in front of 40,490 fans at Patersons Stadium.
The Eagles had their chances, losing for the fifth time this season when having more scoring shots than their opponents.
But they were also held goalless in the third term when best afield Stephen Hill, Nat Fyfe and David Mundy got to work in the Fremantle midfield and the Dockers' trademark pressure strangled the Eagles.
The game looked over at three-quarter time after the Dockers kicked five goals to none to lead by 24 points at the final change.
But the Eagles midfield bounced back at the start of the last term, led by Matt Priddis, who was the Eagles’ best with 24 touches.
They also found some unlikely heroes with Jeremy McGovern, Xavier Ellis, Patrick McGinnity and Mark Hutchings all kicking clutch goals to see West Coast hit the front at the 15-minute mark of the final term.
But the Dockers again stamped their premiership credentials. Hill took an intercept mark from a kick-in and calmly slotted his third goal, which along with his 32 disposals sealed his Ross Glendinning Medal win.
Danyle Pearce threaded an intelligent dribble kick from the boundary moments later before Hayden Ballantyne kicked the sealer, his third goal, from the next centre clearance.
The Eagles’ woes were compounded by a nasty knee injury to Mitch Brown. He was stretchered off in the third term after landing awkwardly on his right knee. The luckless Brown missed the 2008 season following a reconstruction on his left knee.
The first half was entertaining and free-flowing despite both sides playing a man loose in defence. As a result McGovern, Matthew Pavlich, and Josh Kennedy all showed off their goalkicking prowess from long range.
Tendai Mzungu had a chance to level the scores late in the opening term but just missed.
Incredibly, 4.2 was the Eagles’ highest quarter-time score against Fremantle since round six, 2009.
Wasting chances has been the story of West Coast's season and the second term continued the tale.
The Eagles had 13 inside 50s to 10 only to kick 1.7 to the Dockers’ 2.1 and were fortunate to lead at half-time.
The Dockers would be fancied to stretch their winning streak to 10 with their next four matches against Melbourne, GWS, St Kilda and Carlton. The Eagles' finals hopes are almost certainly over, languishing in 10th place with the Sydney Swans to come next week.