The Australian team, led by Tom Slingsby, controlled the final on the Great Sound after reaching the decider with a race to spare.
They had stretched their lead to 14 seconds by the penultimate leg and held firm in light, patchy conditions to secure a second consecutive event win following their triumph in Rio de Janeiro.
The victory lifted Australia to 45 points at the top of the overall championship standings after five rounds. Defending champions Britain are second on 35 points, with Spain third on 34 after their runner-up finish in Bermuda.
Earlier, Spain made a flying start to Sunday's racing, winning Race Five from start to finish.
The victory was Diego Botin's 20th career SailGP race win. Australia finished second despite being penalised for sailing out of bounds, while France placed third with stand-in wing trimmer David Gilmour onboard.
Australia then stamped their authority on the event by winning Race Six ahead of Switzerland and France, sealing their spot in the final before the last fleet race.
Erik Heil's Germany won Race Seven despite briefly dropping off their foils in a turn, a result that secured their place in the three-boat final alongside Australia and Spain.
Sunday's racing was shaped by unstable breeze and narrow margins near the course boundaries, with several teams penalised as they pushed wide to reduce manoeuvres.
The championship next moves to New York later this month.
