The Falcons trailed by 20 points at quarter time and lost every quarter in a 14.6 (90) to 8.7 (55) defeat.
The Bulldogs rode out some tight early exchanges to secure the win, led by four goals from Craig White and 28 possessions from delisted West Coast player Blayne Wilson.
While both sides took time to find their feet in the first official match of 2015, South Fremantle found its groove first, kicking four goals to one in the opening quarter.
The Falcons fought back in the second but not even Shane Nelson’s 38 disposals and Rohan Kerr’s 25 touches and two majors were enough to surpass the all-round performance of their opposition.
South Fremantle’s Shaun Bewick (25 disposals), Kyle Hams (27) and brother Ashton (25) found plenty of the ball in a winning effort.
West Perth’s Jay van Berlo gathered 20 disposals, with teammate Matthew Guadagnin tallying 19.