Trailing by four points at half-time, the Opals dug in their heels in an exceptional third quarter to out-score the Italians, 23-12.
They consolidated that lead in a defensive fourth period, holding their opposition to just seven points in an eight-point victory.
Italy was able to hit just 32% from the field for the game and 13% from the three-point line and that defensive effort was particuarly praised by coach Brendan Joyce.
"It is always difficult to beat Italy in front of a vocal home crowd," he said.
"It was a game we had to grind out defensively with a tremendous defensive effort from Steph Talbot and Nat Burton."
With five points and six rebounds, Burton had a +/- of +16 and Talbot finished with eight points, four rebounds and a steal for a +17 differential.
Offensively, Liz Cambage was again a force to be reckoned with, collecting 12 points, nine boards and three blocks while Tessa Lavey drained two three-pointers for eight points, two assists and two steals.
The full box score can be found below.
The Opals tour of Italy will continue this weekend with games against Belgium and Cameroon before traveling to France on June 5 for a three-game series against China, Canada and France (all ranked within the top 10 in the world).