Steve on the pace in Townsville
It is the only round without a dirt section, but the short circuit was still jammed with sweepers, chicanes and a long straight, which proved perfect for the Supermoto machines.
Riding in the morning test sessions, Anderson qualified in second place for the first race in the S2 Class, but struggled to get his Aprilia SXV 450 off the line, slipping back to fourth.
However, he climbed back to finish second behind Jarod Koppe on a Suzuki.
In the second and third races, Anderson had better starts. However, he couldn't find a way around the lead rider Koppe and agains finished second each time.
The fourth race was the 15-lap final. Anderson tucked in right behind Koppe into the first corner, then showed great patience to shadow Koppe for 14 laps.
He waited until the last corner to make his move and take the win by half a wheel length.
The All Powers Challenge race was another 15-lap event.
Anderson moved into second by the second turn behind Linden Magee on a Kawasaki, but he slipped to third when Josh McFairlane on a Factory Aprilia SXV 550 overtook both of them to take the lead and go on to win. Anderson finished third.
"I'm so happy with the way this weekend turned out," he said.
"The Aprilia SXV 450 is perfect.
"With practise in Lismore the week before washed out, the morning test sessions were my first real workout since getting the frame and swing arm modified, and it has improved the bike immensely.
"I've never ridden a bike and had so much confidence in the front end before.
"I can only improve further with more time on the machine. A big thanks to North Coast Aprilia, Anderson Pneumatics, my dad Phil Anderson and Ben and Josh from Team SXV for all their help."
Steve Anderson is running second in the S2 class, trailing Koppe by 12 points. He is third in the All Powers Challenge behind McFairlane and Magee.
His next big ride is the Australian Supermoto Championships first round at Ipswich on June 8.