They were among nearly 400 competitors who tackled the 44km course in perfect weather from the top of the Remarkables ski area to the Coronet Peak base area.
The pair have won endurance racing world titles together with Team Avaya (formerly Seagate), and will be joining forces again for the world championships on Reunion Island in November.
Forne, a six-time winner of the Adventure Racing World Championships, said it was now "down-time" in his racing year.
With his next major race in November, the Peak to Peak was an opportunity to gauge his fitness and "keep a bit of sharpness".
"I knew it would be a close race, and I’m a little bit surprised."But that’s part of the fun. These races are always a bit unexpected because you don’t know what sort of training everyone’s done."
Forne was chased home by 17-year-old Reuben Thompson, formerly of Queenstown, who is the national secondary schools under-19 triathlon champion.
Now based in Cambridge, where he is training with the national high-performance team, Thompson said he was "gutted" with second place despite it being his first multisport race.
He had lost a lot of time after coming off his bike in gravel on the Remarkables road.
Queenstown’s Hamish Fleming, who had won the past three races, came in third.
It was the sixth Peak to Peak win for Wanaka physiotherapist Williams, originally from Northern Ireland, which makes her the event’s most successful individual.
The 43-year-old said she decided to do the race again to "shock" her into training.
"It’s been hard, with the snow being so good this winter, to go running, biking and paddling, so I’ve been quite distracted."
The race started with a ski or snowboard down The Remarkables ski area’s Outward Bound run, a mountain bike ride down the access road to Frankton Beach, a kayak paddle to Queenstown Bay, a run to Arthurs Point and a climb by road bike to Coronet Peak.
Event director Geoff Hunt said it was the perfect training programme for athletes gearing up for longer events like the Coast to Coast.
"The weather couldn’t have been better and the feedback has been really positive."
Results
Veteran team — Avanti PlusMixed team — Silver Anniversary Of The Famous FiveBusiness team — Fulton Hogan TerminatorsOpen team — Ryan Shanks FitnessJunior male — Will MorshuisVeteran male — Rikki GriffinVeteran woman — Alex MartinOpen women — 1: Joanna Williams, 2: Alisa Rollinson, 3: Meg BichardOpen men — 1: Chris Forne, 2: Reuben Thompson, 3: Hamish Fleming
