Cassidy now has a 126-point lead in the series and is looking forward to getting to Manfeild and trying to wrap up the TRS championship.
"The ideal thing to do is to have a safe first race at Manfeild, get the points. Pretty much do the same thing in the second and then it's all on for the New Zealand Grand Prix," he said.
"This one is huge [the New Zealand Motor Cup] so is the Grand Prix and to get both of them would be great."
Meanwhile, further down the field the race for the minor championship places has really heated up. Another Kiwi driver, Damon Leitch, held second place in the championship after three rounds, keeping the 15 overseas drivers at bay.
However, in a weekend he'd probably like to forget, he's slipped one place down the ladder to third behind Van Asseldonk, who finished second for the weekend.
It all started with a broken sway bar in qualifying which meant he had to start down the field, which in turn impacted on his next race. Leitch got pinged a 50 secs penalty for causing an incident in race two and so finished 14th.
Things didn't get any better in race three where, with a couple of corners to go, he got tangled up with Jono Lester finishing a lap down.
"Not a very good weekend really, pretty disappointing," said Leitch. "Starting from the rear of the field was always going to make things difficult over the weekend.
"I just seemed to get caught in the middle of all the carnage. I'll just have to head to next weekend at Manfeild and hope we get a bit of luck on our side."
In the reverse grid top six race two, restarted after collisions, Italian Raffaele Marciello bounced out to an early lead and was never threatened by the chasing pack.
STANDINGS
* TRS points after four of five rounds:
* Nick Cassidy (NZ)730
* H van Asseldonk (Neth)604
* Damon Leitch (NZ)587
* Josh Hill (UK)520
* Jordan King (UK)516
* Raffaele Marciello (It)460.