Jeong made the green in two at the par-4 18th but Fisher went through the green and was unable to get up and down and settled for bogey. Jeong two-putted from 35 feet and title home the title.
Jeong started the final round one stroke off the lead but four-putted No. 1 for a double bogey. Had five birdies and 12 pars the rest of the way, however, for a 3-under-par 69.
Fisher had six birdies, including on No. 17 where his tee shot at the par-3 hole ended up 1 foot from the hole, and two bogeys Sunday for a 68-that left him tied with Jeong at 10-under 278 and headed to the playoff.
Third-round leader Brody Ninyette, a local favorite in Western Australia, had three bogeys in the final six holes of regulation and shot even-par 72 Sunday. That left him two strokes off the lead and tied with Dimitrios Papadatos, who shot 68 Sunday, and Danny Willett, who had a 69.