Australia moved into a winning position on a rapid day three of the first Test against Pakistan at the Gabba, though the tourists showed greater grit in their second innings.

Starting the day on 97-8 in their first innings, Pakistan ended Saturday on 70-2 in their second innings, with Australia scoring a rapid 202-5 declared in between to stretch their lead to 489.

A shocking collapse on day two had put Pakistan behind the eight ball, though Sarfraz Ahmed's belligerent 59 not out alongside Mohammad Amir (21) and Rahat Ali (4) at least put Australia captain Steve Smith off enforcing the follow on when the tourists were 142 all out, 287 runs in arrears.

Smith (63) instead turned the screw with the bat, putting on 111 for the third wicket with Usman Khawaja (74) as Australia batted just 39 overs before hoping for magic under the lights from their bowlers.

Azhar Ali (41 not out) ate up deliveries with an assured performance, but there was little sign of those around him being capable of seeing out either a record-breaking chase or block-a-thon.

Opener Azhar's good work was mirrored earlier in the day by Sarfraz, who had faith in allowing Amir to face Australia's quicks but the tail-ender's 69-ball resistance was broken when Jackson Bird (3-23) cut him in half and Smith sharply reviewed a not-out decision, which proved a nick on its way to wicketkeeper Matthew Wade.

Sarfraz got a deserved fifty off Nathan Lyon but the innings was concluded in the next over as Rahat failed to get his bat on the ground when scampering through for a single and David Warner effected the runout with a direct hit.

The hosts were not hanging around as they came out to bat, with Warner (12) and Matt Renshaw (6) both undone while trying expansive efforts.

At 24-2 there could have been panic, but Australia were still more than 300 runs in the lead, allowing Khawaja and Smith to settle things down early in their partnership.

From 40-2 at tea, the pair put on 95 runs in 106 balls before Smith, who reached his fifty with consecutive fours off Rahat, got a leading edge off Yasir Shah (1-45) to Rahat at long on.

Six balls later, Khawaja raised his bat after reaching 50 for the fourth Test in a row and he kept the pedal down alongside first-innings centurion Peter Handscomb before Pakistan captain Misbah-ul-Haq defied his full 42 years to take a superb diving catch and remove Khawaja.

Nic Maddinson (4) fell in the over before dinner, when Smith declared, hoping to repeat the 7-24 collapse of the previous day, but it failed to materialise.

Not that there was a lack of encouragement for the Australians. Sami Aslam (15) and Babar Azam (14) were removed and Younis Khan failed to score from 19 deliveries that saw him hopping in defence of short balls and tumbling to keep Yorkers out, although Azhar's 104-ball 41 not out at least showed the tourists have the technique required to compete in the remainder of the series.