Simson defended the title she won last year, clocking 13h 05m 10s to finish ahead of triathlete and 2013 Australasian multisport champion Simone Maier (13h 24m 12s), and multiple title-holder Elina Ussher (13h 27m 44s).
"The day was extremely bizarre," Simson said. "[It was] the polar opposite to my race last year when my body misbehaved but my mind pushed myself. This year, my body felt great all day but I struggled to push myself to the next level.
"But I executed all my race goals and conserved energy, so I'm pretty stoked with the result."
Currie was in pole position from the start line at Kumara Beach at 6am, leading the 3km foot race to the first Aicken's transition and consolidating his place at the front of a leading group of 11 cyclists battling a head-wind throughout the 55km bike stage.
Clarke's swift changeover saw him first to begin the 33km mountain run through the Mingha Deception trail, but Currie's renowned running saw him reclaim the lead as they climbed to Goat Pass.
"At one point, I looked around and randomly saw him and I really didn't expect to see him," Currie said. "I tried to push as hard as I could and I knew if I did and he tried to stay with me, then it was going to hurt him, so I think it must have."
The Wanaka local had carved out a five-minute lead when he emerged at Klondyke Corner for the third transition on to the bike - for the 15km ride before the 67km kayak stage through the Waimakariri Gorge. The river stretch saw Currie go from strength to strength, building a 10-minute lead despite the low water levels from a hot and dry summer.
"I had a fair idea that if I didn't see him before Woodstock, then I could probably hold him off," he said.
After disembarking at Iron Bridge, Currie was met with near-perfect conditions to set out on the fourth and final stage, making short work of the 70km ride to the finish.
Maier led early in the women's race, being among the second pack to arrive at the Aicken's transition four minutes ahead of Simson.
The eventual winner warmed into her work and overtook her rival to establish a three-minute break before Goat Pass, with Ussher trailing the pair through Klondyke Corner.
The kayak section gave hope to Ussher's supporters, including husband, five-time champion and 2015 race director Richard Ussher, as she climbed out of the water in second but she faded on the ride.
The two-day event saw Kevin O'Donnell winning the men's individual race and Olivia Spencer-Bower top the women's event. David Skipwith travelled to Christchurch with the assistance of ThermaTech.
