A century to keeper-batsman Jet Liebke was not enough to see Australia Under 16s to victory, with Pakistan scoring a final-over win in the fifth one-day match at the CitiPower Centre.
The win sees Pakistan reduce the series deficit to 3-2, ahead of Friday's Twenty20 clash to round out the series.
Australia won the toss and elected to bat in Game 5, posting 5-258 from their 50 overs.
Queenslander Liebke (101 off 141 deliveries) was the mainstay of the innings, blasting nine fours and two sixes after opening the innings.
He found strong support from fellow opener Kyle Brazell (57 off 83) from South Australia, and first-drop Yash Pednekar (58 off 58) from Victoria.
Liebke and Brazell combined for a 134-run opening partnership, before Liebke and Pednekar combined for another 94 runs.
Jake Fraser-McGurk (15 not out off nine) provided a late cameo.
In reply, Saim Ayub was the star for Pakistan, smashing an unbeaten 161 off just 151 deliveries to carry his bat through the innings.
Ayub cleared the fence on five occasions, scoring more than 60 per cent of his team's runs.
Hassan Kiani (35 off 50) also made a strong contribution, as Pakistan won with four balls to spare.
Queensland's Will Sanders claimed 4-50 to be the pick of the Australian bowlers.