Group A, Johannesburg: Australia 310-8 (50 overs) beat Pakistan 228 all out (45 overs) by 82 runs
Australia quashed some late resistance from Pakistan to win their World Cup opener on Tuesday.
Despite the absence of star leg-spinner Shane Warne, Australia's attack proved too much for Pakistan's batsmen.
Rashid Latif and Wasim Akram did their best to halt the fall of wickets late on, but faced a losing battle reaching the imposing target of 311.
Andrew Symonds became an unlikely hero for Australia, notching up his first international century with an unbeaten 143 in the morning before making a brilliant diving catch for the key wicket of Yousuf Youhana.
Symonds took the game away from us and we really struggled in the later
Pakistan captain Waqar Younis
It was a relief for Australia, who had suffered a disastrous start to the day.
They were hit by a major blow, even before the toss of the coin, as Shane Warne was forced to pull out at the last minute for failing a drugs test.
Pakistan then piled on the pressure by taking four early wickets to leave the favourites reeling on 86-4 before Symonds and captain Ricky Ponting dug in.
The Birmingham-born all-rounder added 60 for the fifth wicket with opener Ponting, who was finally caught off fast bowler Shoaib Akhtar for 53, and 70 for the sixth with Brad Hogg.
Confidence turned to frustration for Pakistan, who had made such a positive start to their opening match.
Symonds steps out to form a crucial fifth wicket partnership with Ponting on his way to an unbeaten 125...
World Cup veteran Wasim Akram dismissed Adam Gilchrist in his third over and then removed Matthew Hayden and Damien Martyn with successive deliveries before Pakistan captain Waqar Younis sent back Jimmy Maher.
But later on in the morning he was ordered out of the attack after bowling two beamers and his side were penalised an over because of their slow bowling rate, leaving them to score 311 for victory from 49.
Pakistan then made a stuttering reply as all the Australian bowlers chipped in.
Wasim and Latif made an entertaining eighth-wicket stand, top-scoring with 33 each to raise faint hopes.
But when Glenn McGrath produced a stunning catch at extra cover to dismiss Waqar and give Harvey his fourth wicket, Pakistan's late show was finally over.
Australia: Ricky Ponting (captain), Adam Gilchrist, Matthew Hayden, Damien Martyn, Jimmy Maher, Andrew Symonds, Brad Hogg, Ian Harvey, Jason Gillespie, Brett Lee, Glenn McGrath. 12th man: Andy Bichel .
Pakistan: Waqar Younis (captain), Taufeeq Umar, Shahid Afridi, Saleem Elahi, Inzamam-ul-Haq, Yousuf Youhana, Younis Khan, Abdur Razzaq, Rashid Latif, Wasim Akram, Shoaib Akhtar. 12th man Mohammad Sami.
Umpires: David Shepherd, England, and Asoka de Silva, Sri Lanka.
Television umpire: Billy Bowden, New Zealand.