USA went ahead after four minutes when Vince Grella dwelt on the ball too long and Buddle stole it. The striker took three steps and unleashed a perfect right-foot shot that easily beat Mark Schwarzer.
Australia started to win more possession but were hit on the break in the 15th minute when Clint Dempsey?s through ball found Robbie Findley in the clear and he did well to round Schwarzer only to miss a gaping goal with his shot.
USA continued to be a threat on the break and Dempsey nearly restored the lead with a shot Schwarzer tipped around the post.
In the 31st minute, the Americans did get their second goal as right-back Steve Cherundolo?s cross picked out Buddle at the back post and he made no mistake with a header.
Australia should have levelled soon after when Cahill?s cross was met by Josh Kennedy, but his header went wide off a post.
Hahnemann was called into action almost immediately, but Kennedy wasted another good chance from a Scott Chipperfield cross.
A sublime through ball from Landon Donovan then set up Buddle for his hat-trick, but he unselfishly squared to Findley, who saw his shot bounce back off the crossbar.
Dempsey followed up with a header into the net only to be ruled offside.
Gomez eventually made the game safe for the first Group C rivals of England when he slammed home Donovan?s cross three minutes into injury time.
Source: AFP Global Edition