After Australia won the opening match, Pakistan drew level last Thursday, and have now sealed an impressive ODI series with a dominant showing on Saturday.
Following a disappointing Australian batting performance, Pakistan captain Babar Azam managed a second century of the series, following up his 114 from Thursday with an unbeaten 105 in the third match.
Australia's innings started woefully, as openers Travis Head and Aaron Finch fell for ducks. Ben McDermott steadied the ship with 36 from 50, while Alex Carey top scored for Australia with 56 from 61.
Sean Abbott was the last to offer any resistence at the Gaddafi Stadium with a tally of 49 from 40, but Australia were bowled all out for 210.
The hosts lost Fakhar Zaman early on, but that allowed the introduction of Azam, who went on to form a formidable 190-run partnership with Imam Ul-Haq.
Imam managed an unbeaten 89, hitting six fours and one six in the process. But Azam stole the limelight with his unbeaten 105, which included a remarkable 12 fours.
It marked Azam's 16th ODI century - the second most by a Pakistani batter, with only Saeed Anwar's 20 out in front.
Imam also leaves the series with a record of his own, too. The 26-year-old broke the long lasting record of England's Graham Gooch for the most runs earned against Australia in a three-match ODI series - Gooch previously held the record with 289, but Imam's 298 means he now tops the charts.
The two sides will now have a three day break before returning for a one-off ODI match on Tuesday.