Western Australia 437 for 6 (Whiteman 188, Bancroft 91, Bell 2-64) trail Tasmania 439 by 2 runs
Western Australia opener Cameron Bancroft fell short of consecutive Sheffield Shield centuries, but captain Sam Whiteman made Tasmania toil on a flat WACA pitch as the match appears headed for a draw.
Whiteman batted the bulk of day three as WA almost reached parity by stumps. Facing 383 balls, Whiteman was agonisingly short of his highest first-class score of 193.
WA's strong reply was built on a 227-run opening partnership between Whiteman and Bancroft as Tasmania's attack struggled to penetrate in batting friendly conditions.
Some long-time WACA observers had wondered whether it was the dullest pitch at the famous ground since the 2015 New Zealand Test, which seemingly hastened Australia quick Mitchell Johnson's retirement.
But Bancroft missed a golden opportunity of making another century after his 122 in WA's big opening victory over Victoria. He is in a race among several contenders to replace veteran opener David Warner, who is expected to retire from Test cricket this summer.
Tasmania had some respite with temperatures significantly cooler than the oppressive heat over the first two days. As cloud covered the ground late in the day, their quicks finally enjoyed belated assistance with seamer Gabe Bell conjuring reverse swing.
Resuming on 63 not out, Bancroft survived a big lbw appeal from Bell early before he blunted the attack much like during the latter part of day two.
With WA still facing a large deficit, Bancroft and Whiteman batted cautiously with the occasional boundary a welcome sight from the continual stout defending.
With Tasmania's bid for a wicket appearing forlorn, the main interest was centred on who would score a century first with Bancroft and Whiteman neck and neck for much of the innings.
But with Bancroft intent on stonewalling, Whiteman inched away and notched his first century of the season with a pull shot to the boundary off seamer Mitchell Owen.
All eyes after lunch were on Bancroft, whose inevitable march to another ton was denied when spinner Jarrod Freeman trapped him lbw seemingly out of nowhere.
Bancroft, along with those at the ground, could not believe he missed a sweep shot, but his dismissal triggered a succession of wickets not seen since the opening session of the match.
After starting the season strong with 94 against Victoria, teenager Teague Wyllie was plumb lbw to hard-working Bell for 4. Wyllie can sometimes seem glued to the crease, especially early in his innings, and that was again the case here.
Bell was further rewarded when an impatient Hilton Cartwright holed out as WA inexplicably lost three wickets in seven overs. Cartwright, who played two Tests as an allrounder for Australia, made his return from a knee injury but is playing as a specialist batter.
In a rare recent sight, clouds started to form overhead to further improve Tasmania's mood but normal resumption resumed with Whiteman and Aaron Hardie making it look rather easy.
Perched on 149 at tea, Whiteman quickly reached another milestone after resumption while Hardie played aggressively to score an attractive half-century.
Hardie, who recently made his international debut, performed well against Victoria with 48 and five wickets for the match. He eyed a big score, but on 56 hit Freeman straight to short extra cover.
Bell welcomed the increasingly gloomy conditions, but wickets remained few and far between to further underline this uncharacteristic WACA pitch.
