Steve Smith continued to turn the screws on a listless West Indies and notched his fourth Test double century before Australia declared their massive first innings shortly after tea on day two of the first Test.
Fifteen minutes into the final session, a near-flawless Smith reached the landmark with a single off spinner Kraigg Brathwaite but Travis Head chopped onto his stumps on the next delivery to fall for 99.
Head's dismissal brought a close to Australia's massive first innings, where they batted for 152.4 overs to vindicate skipper Pat Cummins' decision to bat first.
Smith's concentration never wavered through the day, even when the match meandered amid a smattering of fans, who started to create their own excitement by mocking West Indies' sloppy fielding. He also reinforced his penchant for his new refined technique, where he has eradicated shuffling across the crease.
After a disciplined start earlier in the match, West Indies were unable to conjure fireworks on a surface with a strip of grass down its middle.
Amid overcast and cooler conditions, a relief after warm weather on day one, West Indies' batters will need to take heed of an imperious Smith, who powered Australia past 500 with an audacious boundary over deep third to further exasperate quick Alzarri Joseph.
Just before lunch, Smith equalled Sir Donald Bradman with his 29th Test century. He reached the milestone with a single to long on, who was strangely not brought in to restrict the run.
In the process, Smith also passed 4000 Test runs at home. Only Bradman (98.22) and Sir Garfield Sobers (66.8) have better home averages than Smith's 64.53. He also continued his dominance over West Indies, who he currently averages over 200 against in six Tests.
Starting day two in a commanding position at 293 for 2, Labuschagne and Smith pummelled West Indies with a 251-run partnership as they batted almost through the entire first session. Labuschagne reached his second Test double century just before lunch, celebrating by taking off his helmet followed by a hearty wave of his bat. Two balls later, out of nowhere, he was dismissed just short of his highest Test score of 215 when he edged the spin of Kraigg Brathwaite to wicketkeeper Joshua Da Silva. After aggressive captaincy earlier in the innings from Brathwaite, who implemented attacking fields complete with five slips, he mostly sought a defensive approach and might face further criticism for his use of the bowlers.
Joseph and fellow quick Jayden Seales were surprisingly not used in the first hour despite West Indies needing early wickets to claw back into the contest. Allrounder Jason Holder bowled alongside spearhead Kemar Roach to start the day's play and his towering height was able to conjure occasional steep bounce, but the batters were up to the task by cleverly steering through the gaps behind the wicket. In what would have particularly frustrated coach Phil Simmons, who believed his team endured a luckless performance on day one, Labuschagne narrowly missed dragging onto the stumps off seamer Kyle Mayers, who was perhaps underused the previous day after impressing with a superb delivery to dismiss Usman Khawaja.
Labuschagne had more luck on 194 when he edged spinner Roston Chase only for Da Silva to miss a chance behind the stumps.
It continued their poor fielding performance as West Indies' hopes of turning around two decades of Test misery in Australia nosedived.