Marnus Labuschagne posted a career-high 185 and David Warner contributed 154 as the top three batsmen scored 436 of Australia's 580 first-innings runs in the first Test against Pakistan.

Pakistan's first three wickets fell within seven overs in the second innings late on Saturday to conclude a lopsided first three days in the series-opener at the Gabba, where the Australians haven't lost a Test since 1988.

Pakistan were 64-3 at stumps with two days to play, still 276 runs in arrears with seven wickets in hand.

Just like the batting lineup dominated an inexperienced attack, Australia's fast bowlers were right on top.

Mitchell Starc, who took four wickets in Pakistans first innings of 240, added another two in his first spell in the second. The left-arm paceman trapped Pakistan captain Azhar Ali (5) lbw in the third over with the total on 13, and five balls later had Haris Sohail (8) caught behind to make it 25-2.

Asad Shafiq, the leading scorer in Pakistan's first stand, didn't get off the mark before getting a thick edge off Pat Cummins to Steve Smith at second slip and it was 25-3.

Shan Masood (27) and Babar Azam (20) survived until stumps and have a lot more work to do if Pakistan is to salvage the Test.

That the Australian top-order found form on the true, bouncy pitch at the Gabba was surprising to nobody. The only quirk was Smith's dismissal for four from 10 balls, making him the lowest scorer of Australia's 11 batters despite a relative tail-end collapse when the last five wickets fell for 35 runs. Smith was almost immovable for the England bowlers in the Ashes, when he scored 774 runs in seven innings to lead the scoring. Yasir Shah certainly has Smith's measure, dismissing the ex-Australia captain for the seventh time in Tests.

For all the runs he saved by getting Smith out early, though, Yasir still finished with an unwanted record in the column for runs conceded. His figures of 4-205 from 48.4 overs made him the first bowler to concede 200-plus runs in a Test innings three times. And two of those have been against Australia.

The leg-spinner had to shoulder extra load after 16-year-old Naseem Shah did no further bowling after having Warner caught behind by Mohammad Rizwan during a four-over morning spell.

It gave Naseem, the youngest player to make his Test debut in Australia, his first wicket at cricket's most elite level. That could have come on Friday, when he had Warner caught behind for 56, but for a no-ball that gave the Australian veteran a reprieve.

Naseem finished with 1-68 but was restricted to 20 overs. Another young paceman, 19-year-old Shaheen Afridi, picked up two late wickets to return 2-96 from 34 overs and part-timer Sohail had both Matthew Wade (60) and Travis Head (24) caught behind to finish with 2-75.

Bowling coach Waqar Younis said his bowlers didn't get their lengths right in the Australian conditions and were punished for it, but he defended the selection of his attack in terms of a valuable learning process.

He said Naseem's workload had to be managed carefully, hence his reduced output on day three.

"He is the future for Pakistan. We have to use him sensibly, smartly," Waqar said. "That's what the captain did. (Naseem) is a wicket-taker. It's just his first Test match."

Labuschagnes maiden Test century soaked up much of the day. He went in with the total at 222 on Friday when Yasir bowled Joe Burns for 97, and he was 55 when Australia resumed on day three at 312-1.

The 25-year-old right-hander wasn't out until after tea, when the score was 546-7, his 279-ball innings stretching into a fourth session before he flashed at a Shaheen delivery and edged to gully.

Labuschagne batted with confidence in his 10th Test and a venue he knows well from playing first-class cricket on the ground. He had an lbw decision overturned on 93 after a review, and his 100 came from an edged boundary after 161 balls. After hitting 20 boundaries, and getting within sight of a double-century, it was a tired shot that ended his innings.

"I love playing here. It's quite an intricate wicket. To come out and do that today, it was great," said Labuschagne, who took a catch as a substitute fielder in a Test here in 2014 and only secured a regular spot in the Test lineup after being used as a concussion substitute for Smith in August during the Ashes series and posting four consecutive half-centuries.

"My career so far has been a bit peculiar, to be honest. I took a catch, wicket and run-out before I got a run. The way it's all unfolded is definitely not the way I pictured it."