Labuschagne was unbeaten on 171 at tea, with captain Tim Paine unbeaten on 13 as the Australians reached 532 for five.
Brisbane: Marnus Labuschagne's maiden Test century helped Australia grind Pakistan down at tea on day three of the first test at the Gabba on Saturday.
Labuschagne was unbeaten on 171 at tea, with captain Tim Paine unbeaten on 13 as the Australians reached 532 for five, a lead of 292 over Pakistan's first innings total of 240.
The South African-born Labuschagne made history during the Ashes series earlier this year when he was brought into the second Test as a concussion replacement for Steve Smith, who had been hit in the head by a Jofra Archer bouncer.
It was the first time a concussion replacement had been used in Test cricket since the new law was introduced.
Labuschagne scored four 50s in that series but had been unable to convert any of those until his near chanceless innings at his home ground in Brisbane.
Earlier, teenage pace sensation Naseem Shah claimed his first Test wicket when he had David Warner caught behind for 154.
The Pakistan pace bowlers attacked Warner from around the wicket on Saturday and the 33-year-old struggled to get the ball away.
Warner only added three runs to his overnight score of 151 when he became 16-year-old Naseem's first victim in Test cricket.
Naseem, whose pace has been impressive during this Test, eventually claimed Warner when the nuggety opener was unable to avoid a short pitched ball and edged it to wicketkeeper Mohammad Rizwan, to leave the Australians 351 for two.
The Pakistanis' hearts must have sunk when they saw Steve Smith striding to the crease to replace Warner.
But after hitting a boundary off Yasir Shah, the leg-spinner then clean bowled Smith, the seventh time in six Test matches that Yasir has dismissed the Australian number four.
Labuschagne and Matthew Wade shared in a 110-run partnership before Wade was well caught by Rizwan for 60 off Haris Sohail.
Sohail and Rizwan then combined to have Travis Head caught down the leg side for 24.
Labuschagne will be looking to bring up a double century after tea before a possible late declaration.