Victoria, defending champions in the domestic competition, produced another abject batting performance to lose by an innings and 107 runs with more than a full day's play remaining.
The visitors had been dismissed for just 155 in their first innings at the Western Australian Cricket Association ground while their hosts compiled 464 in reply, with opener Mike Hussey finishing on 223 not out.
Victoria were then skittled for 202 on Tuesday with Jonathan Moss, who made 55 and Matthew Elliott with 53 offering the only resistance, compiling an 88-run stand for the third wicket.
For Western Australia Brad Williams with 3-45, and Darren Wates 3-70 were two of the chief destroyers.
The win put Western Australia top of the Sheffield Shield table for the first time since 1999.
In Hobart, Queensland batsmen Brendan Nash and Craig Philipson hauled their team out of trouble on the opening day of the match against Tasmania at Bellerive Oval.
Queensland had been reeling at 29 for three before Nash with 92 and Philipson with 119 shared in a fourth-wicket stand of 191 runs to save the visitors from a disastrous day.
At stumps Queensland were 394 for nine at stumps.
In Adelaide, New South Wales batsmen Phil Jaques and Dominic Thornely scored half-centuries as their team made 298 on the opening day of the match against South Australia at Adelaide Oval.
At stumps, South Australia were 23 for two in reply after paceman Matthew Nicholson dismissed openers Tom Plant for a duck and Luke Williams for 14 to have figures of 2-4.
For New South Wales, opener Jaques' free-flowing innings of 82 was the highlight of the day coming from 125 balls, with 11 fours and two sixes.