He was lucky to escape from the crash with only bruising. Ironically, the crash on lap 10 of the 12-lap race, worked to his advantage.
Because he couldn't remove himself from the track, the race had to be red-flagged. The rules state that in a red-flagged race the results are taken from the previous lap, giving Coutts the win because he was leading the F2 class at the time.
Although he was in no condition to jump around in joy, Coutts was pleased with his weekend after winning all of his races in the pre-1989 F2 class.
"I'm still trying to find out the limits of the bike I've just finished building and now I know not to be too greedy with the throttle," he said and laughed.
More than 330 riders took part in the Trans-Tasman Challenge, which provided some great racing despite wet weather that forced riders to use wet tyres for some races.
The Australians turned up with some exotic machinery and world champion riders.
Veteran Robbie Phillis, former World Superbike and World GP rider, beat the field in the pre-1982 F1 class on his 1982 Suzuki Katana 1100. He thrilled the crowd with 200-metre power stands, displaying how much power could be produced from a modified 30-year-old engine. Phillis briefly partnered Kiwi Aaron Slight in a World Superbike team in the 1980s.
TT Isle of Man champion Australian Cameron Donald wore the No1 plate for the Trans-Tasman Challenge. He won all his races despite being closely pushed by Kiwi Hayden Fitzgerald.
The Kiwis narrowly outpointed the Aussies in the Trans-Tasman series with Coutts saying some of the visiting team's riders struggled in the wet weather.
Kerikeri's Patric Nussbaum, riding a modified 1988 Kawasaki ZX10, finished fifth overall in the F1 pre-1989 class.
Nussbaum finished third in the rain on Saturday but a breakdown on Sunday meant he completed only one race.