"I'm really enjoying the new power of the two-stroke and it seems to get good starts - except for the last race," said the 18-year-old Lamont, who races for Moto City Suzuki when back home in New Zealand.
"Qualifying went well for me. I was fourth fastest with two laps to go and then I put in a fast one and ended up qualifying fastest. Having the first gate pick helped a lot.
"The track was quite similar to Whakatane.
"I had a moment in the first race and crashed, dropping to eighth. I got up to second.
"In race two I got the holeshot and led from start to finish to win it.
"In the third race, I was 25th through the first turn and got back into the top 10, finishing seventh, so it was a good result."
It is tight at the top with Lamont now just 13 points off the leader, Australian Dylan Long.
"I've caught up a lot of points now after a disastrous second round [when he ended the day down in eighth position]. Bad starts cost me at round two but I'm much happier on the two-stroke," he said.
Meanwhile, fellow Kiwi Josh Coppins continues to lead the open class in Australia.
Motueka's Coppins (Yamaha YZ450F) is 20 points clear of Britain's Brad Anderson, despite finishing only fourth overall at Wonthaggi.
Former Grand Prix star Coppins finished overall runner-up at round one last month and then backed that up by winning the day at round two at Coonabarabran, New South Wales.
Another New Zealander, Mt Maunganui's Cody Cooper (Suzuki RM-Z450), is seventh in the open class across the Tasman, while Christchurch's Justin McDonald (Honda CRF250) holds on to ninth spot in the MX2 (250cc) class.
The series heads west for round four at Wanneroo in Western Australia this weekend.
