The win lifts West Coast to seventh, and while Fremantle are still in the eight, they have St Kilda at Telstra Dome next week, while West Coast takes on the struggling Melbourne in Perth.
The 13.15 (93) to 6.9 (45) win should have been confirmed by half-time, but West Coast, who had 6.1 early in the second term, then booted 1.9 for the rest of the term.
West Coast dominated all day, but as has been their wont this season, kicked poorly and failed to put the opposition away until the final term.
Things went wrong for the Dockers before the first bounce, when high winds forced the deflation of the pair of giant anchors either side of the scoreboard, and they then lost Roger Hayden with a broken leg in the first term and Byron Schammer in the second with an injured shoulder.
Both teams had changes before the bounce, with West Coast skipper Ben Cousins missing his sixth consecutive game with a back-related hamstring, while Luke McPharlin also missed his sixth with a broken collarbone.
West Coast's revival has been built on the dominance of its midfield and nothing changed today.
West Coast's runners simply ignored their tags, running harder, tackling more ferociously, using the ball far better.
Chad Fletcher continued his sublime second-half of the season, collecting 38 disposals on the way to his second Glendinning medal.
Chris Judd, Daniel Kerr, acting skipper Chris Judd, Michael Braun, Chad Morrison, Sam Butler, Josh Wooden and veteran Drew Banfield all joined in.
Darren Glass was terrific on Troy Simmonds, and David Wirrpunda and Adam Hunter gave tremendous drive off half-back.
For the Dockers, Robbie Haddrill did a terrific job on Andrew McDougall, while Justin Longmuir was good early, although Dean Cox continued his excellent season.
The Dockers got on the board first when Justin Longmuir goaled, but West Coast then booted two in the next two minutes through Phil Matera and Judd.
McDougall then goaled from a tight angle but Farmer replied with a bizarre running goal that he made much more difficult than it should have been.
Brent Staker and Wooden finished the term with majors and West Coast led by 17 at quarter time.
Shaun McManus got the first of the term for the Dockers after a lovely tap from Aaron Sandilands, but Hunter and then Ashley Sampi goaled and the visitors led by 30 at the long break.
Sampi started the scoring in the third with a snap from 30 after a handball from Andrew McDougall.
Fremantle then strung two goals together for the first time in the match when Troy Simmonds and Des Headland goaled, but a Staker major - from the intersection of the boundary line and the 50-metre arc after the siren - restored the half-time margin at the last break.
Peter Bell kicked a goal in the second minute of the term, but that was the last goal for the Dockers as West Coast rolled home.
Eagles coach John Worsfold said he was extremely pleased with his team’s form against the Dockers.
"Comparing to our previous few weeks, that was probably the equal of some our real good work over the last couple of months," he said.
"The conditions were a little bit tricky, so we made our share of ball-handling errors, but in the conditions we were pretty good.
"The midfield were good, but our backline was very good as well. I was delighted with our 22 contributors this week.
"Our midfield have been touted as having a lot of talent, they did their part today and their team-mates followed."
Worsfold refused to talk finals, only focusing on next week's clash with Melbourne.
Fremantle coach Chris Connolly conceded his team was not playing well.
"There's no doubt we're out of form at the moment," he said.
"I thought our defence held up fairly well. We kept West Coast down to a beatable score through pressure.
"Our skill execution, the way we thought through trying to score ourselves really affected ourselves - I think that's been a problem (in the last few games)."
Fremantle: 2.2 3.4 5.8 6.9 (45)
West Coast: 5.1 7.10 9.14 13.15 (93)
Goals: Fremantle: Longmuir, Farmer, McManus, Simmonds, Headland, Bell
West Coast: Judd, Matera, Staker, Sampi 2, McDougall, Wooden, Hunter, Kerr, Adkins
Best: Fremantle: Haddrill, Longmuir, Parker, Bell, McManus
West Coast: Fletcher, Wirrpunda, Kerr, Judd, Hunter, Glass, Braun, Cox
Injuries: Fremantle: Hayden (broken right leg), Schammer (left shoulder)
West Coast: None
Changes: Fremantle: Siegert in for McPharlin
West Coast: Butler in for Cousins
Reports: None
Umpires: Allen, Ellis, McInerney
Crowd: 41,907 at Subiaco Oval
