Mitchell Starc took 3-33 as Australia dismissed Pakistan for 203 in the first game of their three-match one-day international series on Monday at the MCG.
Newly appointed skipper Mohammad Rizwan top-scored with 44 for the visitors but they struggled against some precision bowling, all out in the 47th over.
In Pakistan's first 50-over game since last year's World Cup, Australia skipper Pat Cummins won the toss and opted to bowl on a fine day.
Starc broke through in the third over with Saim Ayub chopping onto his stumps, mis-timing a rising ball before a subdued crowd at the cavernous Melbourne Cricket Ground.
That brought Babar Azam to the crease, unburdened by the captaincy after quitting last month.
He upped the tempo before Starc struck again, with Abdullah Shafique caught behind for a tame 12 in a superb opening spell from the speedster.
Azam was in decent touch and put on 39 with Rizwan before spinner Adam Zampa entered the fray and broke the partnership, bowling Azam for 37 with his fourth delivery.
His replacement Kamran Ghulam lasted just six balls, no match for a brutal Cummins bouncer, gloving to wicketkeeper Josh Inglis to leave Pakistan struggling on 70-4 after 19 overs.
A patient Rizwan played himself in before opening the bat, hitting the first six of the day off Starc. But the wickets kept falling.
Salman Agha was smartly taken at square leg for 12 by Matt Short off Sean Abbott and Rizwan then departed attempting a sweep from part-time spinner Marnus Labuschagne, caught by Inglis.
Shaheen Shah Afridi hit an entertaining 24, but Starc again struck, rattling his middle stump, before a flurry from the tailenders pushed Pakistan beyond 200.
Naseem Shah, coming in at nine, added 40, an innings that included four sixes, with 20 taken off one Zampa over.
MB
