Hamilton, who was No. 2 in last year's drivers championship, avoided the carnage behind him for his fifth victory in 18 GP starts. The 23-year-old British driver was 5.4 seconds ahead of BMW Sauber's Nick Heidfeld in second place and 8.1 ahead of Williams' Nico Rosberg in third.
Defending champion Kimi Raikkonen's Ferrari ran out of gas as he entered the pits with only five laps to go.Only seven of the 22 cars on the grid finished the 58-lap race.
The race ended at turn 1 for four cars and five were out by the end of the first lap on the 3.295-mile Albert Park circuit.
Fernando Alonso, the two-time drivers champion who is back at Renault after a season at McLaren, moved up from 11th on the grid to finish fourth. It was the first time since 2003 that he did not finish on the podium at Melbourne.
Hamilton's McLaren teammate Heikki Kovalainen was fifth, followed by Honda's Rubens Barrichello and Williams' No. 2 Kazuki Nakajima.
our-time Champ Car series winner Sebastien Bourdais did not finish his F1 debut for Toro Rossa because of engine failure with two laps to go but was classified eighth.