The national MX1 champion from Mount Maunganui was simply unstoppable during senior action on Sunday.
Cooper (Honda CRF450) won all three MX1 races, each time crossing the line ahead of fellow Kiwi international Kayne Lamont, of Mangakino, with Tauranga's Royden White completing the podium.
Then, remarkably, Cooper also lined up to race the 125cc class, dusting off an old 2003-model Honda CR125 that had been sitting in his garage since he last raced it in serious competition, 13 years earlier.
He was kept honest by rising young star Scott, but Cooper's 2-1-1 score-line gave him the overall win. Scott finished 1-2-2.
Bulls rider Riley Campbell (KTM) claimed the third step on the 125cc podium.
"Riding in the 125cc class was just a bit of fun for me," said the 33-year-old Cooper afterwards.
"The bike has had virtually nothing done to it since I won the national 125cc title on it (as a 20-year-old) in 2003. It even has the same tyres on it from when I last raced the bike. We just put a new seat cover on it and some new plastic guards, then filled up the tank with fresh fuel.
"I think I'll race a few club events on it this year. It was so much fun to ride again.
"I'm feeling great at the moment and I'm really looking forward to the nationals (which kick off near Timaru in February).
"I usually have October off, just to have a rest from racing, but I think I'm a long stronger and faster now than I was at the same time last year. I'm ahead of where I thought I'd be, although I'm feeling pretty tired now. It's been a while since I've raced two classes on the same day."
Cooper and Collins now look ahead to racing the Auckland Motocross Championships on December 3-4, followed by the Honda Whakatane Summercross just after Christmas and then the big annual Honda New Zealand Motocross Grand Prix at Woodville in late January.
The four-round nationals kick off in February.