Duncan arrived at the weekend's sixth and final round at Villars-sous-Ecot, in France, trailing Dutch Yamaha rider Nancy Van de Ven by just two points and, with just five points to separate the top four riders, anything was still possible. But that's when everything went horribly wrong for Duncan.
She was out in front of race one on Saturday, with a massive 20-second lead over Fontanesi, when, on the final lap, she had to take evasive action to avoid a group of riders who had fallen on a steep jump face. Duncan's bike slid on the muddy grass and became wedged under a fence.
She recovered to finish sixth in that race, but that result had dropped her fourth in the world standings and nine points behind series leader van De Ven with just one race the following day to wrap up the series.
Duncan convincingly won Sunday's final race, crossing the line a whopping 46 seconds ahead of runner-up Livia Lancelot, the defending world champion from France, but Duncan's 6-1 score-card from the weekend was not quite enough and she eventually had to settle for a world ranking of No.3 for 2017.
Fontanesi won the world title by one point from Lancelot, with Duncan third overall, agonisingly just one point further back.
Duncan's Altherm JCR Yamaha Racing Team boss, Motueka's former GP star Josh Coppins, was devastated for Duncan.
"She qualified well and we knew for the racing she'd be good," said Coppins.
She was leading the first race and it was hailing and then there were five girls stuck on the uphill. She crashed trying to get around them.
"We took it (the result) to the jury and they rewound the results to the previous lap (before the track had been completely wrecked, therefore assigning the win to Duncan).
"But then the FIM (the world governing body) took legal advice and decided they hadn't followed the correct procedure with the red (stop race) flag and so therefore they had to revert to the original race result, leaving Courtney sixth instead of first. Deliberations took four or five hours.
"On day two Courtney dominated. She lapped all but one rider, including lapping the new world champion (Fontanesi)," Coppins said.
Duncan and her Altherm JCR Yamaha Racing team is supported by Altherm Window Systems, Yamaha, JCR, CRC, Ados, GYTR, Yamalube, bLU cRU, Fox Racing, Hollands Collision Centre, Star Moving, Ward Demolition, Pirelli, Akrapovic, DID, NGK, Renthal, Motomuck, www.workshopgraphics.co.nz, Motoseat, SKF, Vertex Pistons, Rtech Plastics, Etnies, Mazda NZ, Liv Cycling and Monster Energy.
Main Photo: Courtney Duncan Plows through the heavy conditions