Lunch Pakistan 203 for 6 (Shakeel 12*, Salman 4*) trail Australia 487 by 284 runs
But their hopes faded before lunch when Babar was caught behind from a short-of-a-length delivery from Marsh, who continued his outstanding match after making 90 in Australia’s first innings.
Lyon was just two away from 500 Test wickets in his return after a calf injury cut short his Ashes campaign.
Pakistan’s slide continued when left-arm quick Mitchell Starc clean bowled wicketkeeper Sarfaraz Ahmed, who was retained in the team over Mohammad Rizwan, with an astounding swinging delivery that knocked over off stump.
The flurry of wickets meant Pakistan were facing an uphill task to avoid a 15th consecutive Test defeat in Australia.
Mitchell Marsh claimed the huge wicket of Babar Azam•Getty Images
Pakistan had resumed at 132 for 2 after a stonewall on day two bar some brief urgency from new skipper Shan Masood. Perhaps trying to play more proactively from the get go, Pakistan almost suffered a run out on the day’s first delivery but nightwatchman Khurram Shahzad survived an errant shy at the stumps from Travis Head.
It didn’t matter with Shahzad cleaned bowled by Cummins two balls later to bring Babar to the crease as the match entered a pivotal phase. Cummins immediately tested Babar with short-of-a-length bowling and the occasional bouncer in a riveting contest.
Starc was preferred over Josh Hazlewood, who has dismissed Babar six times in Test cricket. But Babar was mostly consumed with battling Cummins and 20 of his first 22 deliveries were against him.
Babar was pinned down by typically accurate Cummins bowling and he did not get off the mark until his 13th delivery when he blasted a full delivery through the covers for a boundary.
But he had to endure some nervous moments when an inside edge narrowly missed the stumps leading to a frustrated Cummins resorting to a bouncer that flew over wicketkeeper Alex Carey and to the boundary.
With all the focus on that compelling contest, Imam chipped away against Starc at the other end. Having unconvincingly scrapped to 38 from 136 balls during almost two sessions on day two, Imam looked more assured and he needed just 25 deliveries to reach his half-century and help banish the ghosts of a double failure in Adelaide four years ago in his only previous Test match in Australia.
Imam thwarted Starc’s full-length deliveries to provide support for Babar, who overcame Cummins’ terrific five-over spell. Hazlewood entered the attack just before drinks with Babar making an immediate statement with a nice stroke through mid-off.
It was left to Marsh to provide the big breakthrough of Babar after he entered the attack to a thunderous ovation on his home ground. The dismissal sparked even louder cheers as Marsh continued his superb match and triggered a Pakistan spiral.
Tristan Lavalette is a journalist based in Perth