"Not next year, but I would do it again."
Eastcott finished just after 10pm on Saturday, and she received plenty of cheers from the crowd which had braved the rain at the finisher's shute.
"It was an awesome feeling crossing the finish line. I had a rush of youth through that last 100m," she said.
She said the hardest part of the event was the marathon (42.2km run) at the end, which came after a tough 3.8km swim in Lake Taupo and 180km bike ride.
However, she said she never thought about quitting.
"No not at all, I didn't think about giving up."
The 58-year-old teacher took up running only six years ago but she has already got as many marathons under her belt.
She said she decided to take on the challenge of doing an Ironman after cheering on her friends at the Taupo event last year.
Eastcott stopped the clock at 15hr 16min 31sec, finishing well inside the cut off time which was midnight.