Christchurch rider Dylan Walsh (Yamaha) and Taupō's Wyatt Chase (Honda) also figured among the podium finishers but Walsh's hopes of an overall result were dented by a flat tyre in the opening moto.
Tauranga's Brodie Connolly completely dominated the 125cc 2-stroke class. The 16-year-old rode his Husqvarna to winning margins of 45secs, 58secs and 54secs respectively in the three races for a perfect opening round scorecard.
Firmly established in second place with three runner-up finishes is Tauranga's Madoc Dixon (KTM).
The second round of the FOX Motocross Nationals will be hosted by the Rotorua Motorcycle Club at its Highway 30 (Horohoro) track on Sunday February 23. The series then moves to Hawke's Bay for round three on March 1 with the final at Taupo on March 15.
Fox New Zealand Motocross Championship (after round 1):
MX1 (450cc): 1 Cody Cooper (Mt Maunganui) Honda, 75pts; 2 Kirk Gibbs (Australia) Yamaha, 64pts; 3 Hamish Harwood (Takaka) KTM, 62pts; 4 Ethan Martens (Auckland) Kawasaki, 46pts; 5 Brad Groombridge (Taupo) Suzuki, 43pts.
MX2 (250cc): 1 Josiah Natzke (Mt Maunganui) Kawasaki, 63pts; 2 James Scott (Oparau) KTM, 57pts; 3 Maximus Purvis (Mangakino) Yamaha, 56pts; 4 Morgan Fogarty (Australia) KTM, 47pts; 5 Dylan Walsh (Christchurch) Yamaha, 44pts.
125cc 2-stroke: 1 Brodie Connolly (Tauranga) Husqvarna, 75pts; 2 Madoc Dixon (Tauranga) KTM, 66pts; 3 Marshall Phillips (Christchurch) Yamaha, 54pts; 4 Zac Jillings (Rongotea) KTM, 48pts; 5 Ben Wall (Ashburton) KTM, 42pts.