Fourth one-day international, Perth:
Australia 277-8 (50 overs) beat Pakistan 142 (37.5 overs) by 135 runs
Harris (right) celebrates with batting hero Hussey
Ryan Harris took his second consecutive five-wicket haul as Australia won the fourth one-day international in Perth by 135 runs to take a 4-0 series lead.
Australia made 277-8 batting first, with Mike Hussey hitting 67 and Nathan Hauritz 53 not out from 39 balls.
Pakistan were reduced to 39-4, and only 38 from Umar Akmal and 29 from 10 balls from Shahid Afridi allowed them to reach 142 in 37.5 overs.
Harris, who took 5-43 in Adelaide, took 5-19 in only his third ODI.
There is only one game remaining in the series, also in Perth on Sunday.
Queenslander Harris had Salman Butt (0) and Younus Khan (6) caught behind and at one point had figures of 2-0 from 13 balls.
Kamran Akmal (17) and Mohammad Yousuf (10) briefly threatened to steady the Pakistan ship, but Peter Siddle removed both men to leave Pakistan in deep trouble.
Umar Akmal (38) and Fawad Alam (21) produced a painstaking 60-run partnership that was more a battle for survival than any meaningful attempt to overhaul the total.
But when Alam was sensationally run out by Hauritz in the 28th over, Pakistan's chase received a much-needed shot in the arm from Afridi.
Afridi pummelled Hauritz for 17 in one over and hit three fours and two sixes in a typically-flamboyant cameo.
Afridi, though, could only look on from the other end as Harris was brought back into the attack to dismiss Umar Akmal and Rana Naved in consecutive balls.
The explosive all-rounder followed in the next over, Afridi miscuing a delivery from Clint McKay and Hauritz taking a simple catch at third man.
With Afridi gone it was only a matter of time before Australia wrapped up the tail, Hauritz (1-48) taking Saeed Ajmal's wicket before Harris completed the slaughter when he had Rao Iftikhar Anjum spectacularly caught by a diving Brad Haddin.
Pakistan had produced their best performance in the field of the summer, ensuring that most of the Australian top order merely made starts without going on.
Australia certainly appeared to be treating the encounter like the dead rubber it was as they cruised to 190-6 by the 40th over.
But Hussey and Hauritz soon turned that around, laying the platform for another convincing Australian victory.