Van Tuyl put pressure on the two leaders by showjumping clear on Sunday, but Pottinger, has been training with Jeff McVean and improving this phase throughout the season, produced her first clear showjumping round at this level to hold her place, meaning Dalziell-Clout had to do likewise.
They had one rail down to finish second, their best result to date, but it allowed Pottinger to take the title and the spoils.
Pottinger's mother, former Olympian Tinks Pottinger, who lives at Tinui, won the national title in 1985 on another thoroughbred, the former steeplechaser Graphic, raced by her parents Eric and Tiny White. Tinks Pottinger now grooms for her daughter, while a proud Tiny White was there to see her granddaughter make history, no other family having two generations of winners on the Wills Trophy.
The presentation was made by Anton Koolman, who won the first three-day event in New Zealand, at Rotorua in 1966. He had travelled from Sydney, and was impressed by the technical demands of the sport now, although it is no longer a test of real stamina, after the removal of the steeplechase and roads and tracks phases from cross-country day.
ESNZ super league series final result: Katharine Van Tuyl (Palmerston Nth), Double J Sunshine, 306 points, 1; Clarke Johnstone (Matangi/UK), Balmoral Sensation, 210pts, 2; Amanda Pottinger (Waipukurau), Just Kidding, 108pts, 3; Virginia Thompson (Kaukapakapa), Star Nouveau, 102pts, 4; Andrew Daines (Kumeu), Spring Panorama, 96 pts, 5; Giles Gormack (Rangiora), Lucero, 84 pts, 6.