On a day the club celebrated their 1985 premiership win, the hosts were outgunned from the start, falling 38 points behind before they were able to get on the board through Rory O�Brien.
O�Brien�s goal was one of the few highlights for the Sharks, who fell 15.14 (104) to 4.7 (31).
Steven Potente booted three goals for the Falcons, with Trent Manzone gathering 34 disposals to go with two goals. O�Brien led the Sharks for disposals with 36.
South Fremantle faces a difficult challenge to play finals this year.
The Bulldogs fell to Peel Thunder 14.13 (97) to 11.1 (67) at Fremantle Oval on Saturday to sit a game and percentage outside the top five and with a bye this week.