Hilton Cartwright put Tasmania to the sword before a pair of late wickets further put the visitors in the ascendancy
Match Report:
ScorecardCartwright's big ton puts WA in command over Tigers
A superb century from Hilton Cartwright has helped lift Sheffield Shield champions Western Australia to a near-unbeatable position against Tasmania at Bellerive Oval.
Cartwright, who survived a highly contentious caught-behind decision the previous evening on 38, struck 153 to lift WA to 9-460 declared for a first-innings lead of 143 on day three.
Tasmania openers Jake Weatherald (1) and Caleb Jewell (5) both failed to survive six testing late overs after five sessions in the field as they slumped to 2-10 at stumps on Sunday.
It was Cartwright's ninth first-class century, with his 278-ball knock containing 18 fours. The right-hander enjoyed century partnerships with Jayden Goodwin and then Ashton Agar to take the game away from the home side.
It was another grinding day for the Tigers' bowlers with WA failing to rise above three runs an over in an innings of 161 overs.
Goodwin, who resumed on 73, fell six runs short of a second first-class century as he and Cartwright put on 148 for the third wicket.
The partnership had lifted WA to within 51 runs of Tasmania's first innings 317 for the loss of only two wickets when Matthew Kuhnemann made the crucial breakthrough.
Kuhnemann slipped a looping delivery past Goodwin's hitherto impeccable defences to bowl the No.3 and end a 202-ball stay at the crease.
Opening bowler Gabe Bell (2-56) then briefly threatened to change the momentum of the contest with wickets in successive overs.
Captain Ashton Turner was bowled for one before wicketkeeper Joel Curtis was trapped lbw for the same score as WA went to lunch at 5-293, having begun the morning at 2-220.
But Cartwright and Agar halted Tasmania's mini revival with a 158-run sixth wicket stand.
Cartwright eventually edged to wicketkeeper Jake Doran off Kuhnemann, and the left-arm spinner then trapped Agar lbw for 74.
Kuhnemann was rewarded for his 43 overs of toil with 5-100, while Bell picked up 2-56 off 28 overs.
WA went into the match on the back of a six-wicket win against Tasmania a fortnight ago and boasting a slim advantage at the top of the table after two rounds.