The Italians' discipline during crucial man-up situations made the difference as they took advantage of almost all of their power-plays.
Australia fought back in the second half, but by then their opponents had done enough to see out the win.
Italy flew out of the blocks to take a 3-1 lead for the first quarter, as Niccolo Gitto, Danijel Premus and Alex Giorgetti scored from all three of their man-ups.
Australia took just one of their three chances when Tim Cleland found the back of the net.
A crucial moment came in the second quarter when Australia captain Sam McGregor squandered a penalty by straying over the five-metre line.
A goal would have taken the score to 3-2, but the miss triggered an Italian counter-attack and Matteo Aicardi netted to make it 4-1.
Italy went on to put daylight between their opponents as Maurizio Felugo scored a man-up to make it 5-1 before Ritchie Campbell pulled a goal back before half time.
Australia scored the only goal in the third period with a close-range effort from driver Rhys Howden to bring the score to 5-3 to Italy.
Italian Alex Giorgetti opened the scoring in the fourth period, before compatriot Pietro Figlioli took advantage of a man-up to make it 7-3.
Aidan Roach scored a long-range effort for Australia to bring the scores to 7-4, and an unlikely comeback looked possible when a Australian Johnno Cotterill scrambled home a goal to make it 7-5 after an Australian time-out.
However, it was Italy who scored the final goal to win by three.
Italy's conversion rate from man-ups was an impressive six from seven, while Australia only managed one from five.
Elsewhere, reigning Olympic Games champions Hungary suffered a 14-10 defeat to arch rivals Serbia.
The 2008 winners lost to the Beijing bronze medallists in a bruising encounter which saw Serbian driver Andrija Prlainovic score five second-half goals.
Hungary are aiming to win their fourth consecutive Olympic title - their 10th overall - while Serbia are seeking to improve on podium finishes in the last three Games, and clinch their first gold medal since Yugoslavia won in Seoul in 1988.
In the day's other games, Romania beat hosts Great Britain, Croatia overcame Greece, Spain cruised past Kazakhstan and United States edged out Montenegro.