Croft, who hails from the West Coast but currently lives in Wānaka, led the woman's race for several hours before her victory.
Croft was the first woman finisher of this year's 100-mile race at Western States, and came second overall.
The race was won by Adam Peterman, who finished in 15 hours 13 minutes and 48 seconds.
This was Croft's second stab at the 100-mile distance, after an incredible second place in her first attempt at the distance at Western States last year.
Last year, Croft won the 100km race at the Tarawera Ultramarathon in Rotorua outright and is also a previous winner of the 85km Old Ghost Ultra near her hometown on the West Coast.
A few months ago, she also won the Kepler 60km race over the Kepler Track in Fiordland.
The Kiwi, who got into trail running while living in Taiwan and is now a professional runner, also came second at the World Trail Championship in 2019 and won the 2018 Golden Trail Series run.
The Western States Endurance Run is the oldest - and arguably the most prestigious - 100-mile foot race in the world.
The route goes from Olympic Valley to Auburn in California, in the US. Over the course of 100 miles, runners climb about 5485m (18,000 feet) in scorching heat.
