"I couldn't quite win the final race of the day and that would have been a bonus (with an entry into Australia's famous Manjimup 15,000 Motocross event the prize), and I congratulate Hamish Dobbyn for winning that, but the main aim for me was winning the class outright," said Groombridge.
"I charged start gate before that last race because the gate I was using was getting a bit rutted; then I didn't get the traction I wanted. But I'm not making excuses and Hamish rode well to win that last race. I was expecting Hamish to be fast and it's hard to be significantly faster than anyone else on this track or for one rider to completely dominate, so I knew I was in for a fight.
"It was all about consistency today and not hitting the ground (crashing).
"I didn't actually think I would be able to ride today after my big crash at last night's Speedcross. I was a bit sore today but I guess I came up with the goods in the end.
"My fitness is very good and I'll keep working on that as the nationals approach ... there are a few other big events for me to concentrate on too, starting with the Acerbis Four-Hour cross-country race this coming weekend, and then the Auckland Motocross Championships, the annual Whakatane Summercross and the New Zealand Motocross Grand Prix at Woodville.
"I plan to be at an even higher level when the nationals kick off in February."
Bel Ray Pro Rider Suzuki team boss Andrew Hardisty, of Mount Maunganui, was thrilled with his riders' performances over the weekend.
"It was awesome to see Brad launch the new 2015 RM-Z450 so successfully today," said Hardisty.
"Both the track and his opposition were tough, so it certainly wasn't an easy day for him.
"Our two MX2 (250cc) development riders - Dunedin's Campbell King and Te Puke's Logan Blackburn - also placed well. Campbell finished fifth overall but showed great potential to reach the podium, while Logan's introduction into the 250cc class was also very encouraging.
"Logan is new to the class and new to the Suzuki brand, plus he was coming off an injury, so for him to finish sixth overall was excellent."
Groombridge, Carter, King and Blackburn and their Bel-Ray Pro Rider Suzuki team is supported by Bel-Ray Lubricants, Suzuki Pro Rider Programme, Pirelli Tyres, Yoshimura, Oakley, Renthal, O'Neal Racewear, Zeta, DRC, Braking, The Dirt Guide, Talon, Performance Factory, Epic Decals, BikesportNZ.com and Taupo Diesel Solutions.