In just her second match back from the brutal injury sustained last August, Raso raced onto a loose ball inside the United penalty area to give Roar the perfect start at Suncorp Stadium.
The 24-year-old was a constant threat to United's defence, who soon fell further behind after an unmarked Celeste Boureille buried the ball into the back of the net from a 32nd-minute corner.
While Nikki Flannery gave the visitors hope with a goal of her own on the hour-mark, it proved mere consolation as Roar romped towards all three points with further goals from Yuki Nagasato and in-form forward Allira Toby.
The win helped the Roar overtake Perth Glory at the top of the W-League table and left United with little chance of making the finals.
