The 14.9 (93) to 5.7 (37) triumph over the third-placed Swans at Arena Joondalup moved the Falcons back into fifth spot and cut East Fremantle’s hold on fourth to three games after the Sharks were beaten by South Fremantle.
West Perth’s top four chances remain dim, but the side is in a favourable position with a strong percentage and an extra game to play than East Fremantle, which has a bye in round 21.
It casts a new light on the reigning premiers’ clash with the Sharks at Arena Joondalup this weekend.
While a loss for West Perth would make finals action impossible, victory would set up an intriguing finish to the season.
If the Falcons win the three games that follow, then East Fremantle can only survive to September if it wins its final two matches.
That won’t be an easy task for the Sharks, who face finals-bound sides Swan Districts and Subiaco.
One win would not be enough, as it would leave them tied with the Falcons who have a much stronger percentage.
West Perth is a solid chance to win its remaining encounters after this weekend with fixtures against Peel (eighth), Claremont (sixth) and Perth (ninth).
But it will count for nothing if the Falcons lose to the Sharks, who have not lost a game at Arena Joondalup since 2009.
West Perth will be hoping its top players can stand up the way they did against Swans.
Shane Nelson (44 disposals, one goal) Aaron Black (44 disposals, one goal) and Rohan Kerr (39 touches, 16 marks, one goal) won an incredible amount of the football, while co-skipper Luke Tedesco (29 disposals, 16 marks) produced a captain’s performance in the backline.
The Swans had posted just one point to the Falcons’ 7.7 (49) up to half time and did not score a goal until 16 minutes into the third term.
It was West Perth’s first win over Swan Districts at Arena Joondalup in three years.