His time on Saturday is the new men's record for the 42km race, while Crowley's was the best time by a woman. She also holds the fastest women's time for the 25km race, which she achieved in 2015.
As well as the full marathon, the event included 25km, 17km and 10km races and for the first time a Kids Rainbow Dash 2km (7 years and under) and 4.5km (over 7 years).
The 42km race was also an Ultra Trail du Mont Blanc qualifying race. Running the Double Rainbow gave participants two points towards their UTMB qualification, as well as two International Trail Running Association points.
Event director Shaun Collins said the 290 participants was about 100 more than in 2017.
"I think it's a really good variety of terrain. The 10km people stay down around the flats, the 17km go up Rainbow Mountain once and it progresses from there.
"A lot of people sort of start on one of the smaller distances and then progress the next year, it's cool to see people taking on that challenge each year. The kids' race is new this year and that's to encourage the whole family to get involved instead of them having to wait around for mum and dad," Collins said.
He said Hunt's time was impressive.
"He's heaps fitter than last year, so we were expecting a quick time. He's probably gutted he didn't break four hours though."