Ricky Ponting's side looked out of sorts after choosing to bat, crumbling to 176 all out with Umar Gul (3-30) and Abdul Razzaq (2-8) impressing.

Brett Lee took 4-28 in reply to test Pakistan's nerve but Umar Akmal saw them home with an unbeaten 48.

The defeat was Australia's first at a World Cup since 1999.

Pakistan were the victors that day at Headingley too and it was fitting that Abdul Razzaq, the only man in their team to play in both games, should hit the winning boundary.

Not always the most consistent of sides, Shahid Afridi's men were fully focused on this occasion, especially so after an incident during the Australian innings when several players were involved in a heated exchange with Australia's Brad Haddin.

And while Pakistan appear to be coming good at the right time once again, Cup holders Australia will see this defeat as a much-needed wake-up call.

They had not faced a serious challenge in previous games and the result will surely stiffen their resolve ahead of the knockout phase of the competition, where a clash with India looks likely if the co-hosts beat West Indies on Sunday.

Their batting display against Pakistan was an oddly subdued effort and Shane Watson had already been bowled for nine by the impressive Gul before skipper Ricky Ponting was dismissed in controversial circumstances.

Pakistan claimed a catch when he appeared to edge Mohammad Hafeez into the gloves of Kamran Akmal but umpire Marais Erasmus turned down the appeal.

Captain Afridi immediately used a referral which duly revealed a huge nick but an unseemly row had already broken out in the middle and Haddin and appeared to push Younus Khan before Ponting walked off.

With wickets falling, Australia needed Haddin to put the incident out of his mind but he was unable to resist the temptation to throw the bat at a Wahab Riaz delivery, but only managed to edge behind for 42.

Cameron White was run out for eight courtesy of a fine throw from square leg from Misbah-ul-Haq before Michael Clarke missed an attempted pull with a ugly swipe and was bowled by Razzaq.

Mike Hussey (12) failed to find any form before chipping Abdur Rehman to wide mid-on while another fine delivery from Razzaq jagged away and caught Mitchell Johnson's edge to dismiss the all-rounder for a duck.

Resilience down the order is rarely absent when Ponting's side are concerned but even a brisk 25 from Steve Smith could not prevent Australia's lowest World Cup total since 1992.

Early wickets always put the shivers through a dressing room though and when Lee took a sprawling return catch to dismiss Mohammad Hafeez for five, the nerves must have been on edge.

The veteran paceman then trapped Kamran Akmal (23) but a stand of 53 between Younus and Asad Shafiq put Pakistan on course.

But Lee had other ideas and removed Younus (23) and Misbah in successive balls in his second spell - both with fine edges through to the keeper.

Shafique (46) and Umar Akmal steadied the ship again before the former nicked Johnson behind and a brainless heave from Afridi (2) again made things uneasy for Pakistan at 142-6.

But Umar (44 not out) and Razzaq (20 not out) held their nerve to secure a morale-boosting victory with nine overs to spare.