Cooper will now prepare to defend his national MX1 crown in the New Zealand Motocross Championships, the first of four rounds in the series set for Timaru on February 5.
Meanwhile, it was a triple whammy for the Honda camp with Cooper's junior team-mate, Cambridge rider Trent Collins, winning on both days of competition at Summercross.
The 16-year-old Collins, in a transition stage in his racing career where he is classified as a junior but still eligible to race some senior classes, won the Youth MX class on day one at Summercross and then also dominated day two by winning all three junior 12-17 years' 250cc class races.
"You could say it was a brilliant event for me," said Collins.
"But it wasn't just me. So many people who worked behind the scenes should be thanked too, for ensuring I could be on top of the podium both days."
2016 Honda Summercross Senior class winners on Tuesday, December 27:
- Mount Maunganui's Cody Cooper (MX1 class)
- Hamilton's Josiah Natzke (MX2)
- Cambridge's Trent Collins (Youth MX)
- Otago's Courtney Duncan (women's class)
- Rotorua's Cam Negus (veterans' over-35 years)
- Hamilton's Darryll King (veterans' over-45 years)
- Waimauku's Logan Dunn (MX3 support class).
Junior class winners on Wednesday, December 28:
- Cambridge's Trent Collins (junior 12-17 years' 250cc class)
- Mangakino's Maximus Purvis (junior 15-17 years' 125cc class)
- Australia's Adam Smerdon (junior 12-14 years' 125cc class)
- Matamata's Brodie Connolly (junior 13-16 years' 85cc class)
- Australia's Noah Smerdon (junior 11-12 years' 85cc class)
- Wellsford's Wyatt Collins (junior 8-10 years' 85cc class)
- Waitoki's Cole Davies (junior 8-11 years' 65cc class)