Wilson paid just over $500 for Cadet as a 7-year-old.
"It's a real rags-to-riches story - he could be an eventer, too, because he's got all the moves."
The only previous World Cup start the combination had didn't end as well, and in her five other starts with other mounts she has never managed a clear in that opening round.
"Once Cadet jumped that first round clear, I knew we could do it again. He just loved it out there - he'd been jumping well all weekend, and placed in both the 1.4m and 1.45m classes," Wilson said.
Now she is looking forward toward the Farmlands Horse of the Year Show and the JB Olympic Cup. The combination won six one star grand prix together last year, including the North Island championship and at Horse of the Year and this season Wilson has focused on stepping up to the bigger jumps.
Eight combinations came back for the second round, but none could match Wilson's clean slate. She also finished sixth on another mount.
Another Hikurangi rider Nakeysha Lammers, riding Waldorf, won the Country TV Christmas Classic Horse Power and Speed Championship. Hastings' Melody Matherson on Roulette was second with Natasha Lammers riding Tele-Star third. Samantha Peters on Casali finished fourth.
Napier's Olivia Ahlborn and Aorangi Ragtime beat 21 other combinations to take out the Ray Burmester Open Pony Derby 1.2m-1.3m. Auckland's Elmo Jackson finished second while Sharnaye Lammers finished tied with four other combinations for third on two mounts.