Ernie Els claimed his fourth victory in five events this year after winning the Johnnie Walker Classic by 10 strokes on Sunday.
The South African carded a final round of a six-under-par 66 after earlier scores of 64, 65 and 64 to claim victory with a 29 under par tally.
Australians Stephen Leaney and Andre Stolz finished joint second on 19 under for the tri-sanctioned European, Asian and Australasian event on the Lake Karrinyup course.
Els broke a 19-year-old European Tour record by finishing two strokes fewer than the previous best of 27 under par set by Canadian Jerry Anderson at the 1984 European Masters in Switzerland.
He also eclipsed the previous Asian Tour best of 26 under par set by India's Jeev Milkha Singh during the 1996 Asia Cup in Korea.
The world number two won the first two events of on the U.S. PGA Tour and the Heineken Classic this year.