The 17-year-old snowboarder from Wanaka won the slopestyle gold on her qualifying performance at the FIS World Championships in Colorado after the final was cancelled due to bad conditions.
Sadowski-Synnott suffered concussion on her second qualifying run at Park City yesterday, and was not even going to compete in today's final.
"I pretty much found out (she had won) maybe 20 minutes before the medal ceremony - I found out sitting at home resting which was pretty cool," she told Radio Sport today.
"I wasn't riding the course - I wasn't going to compete in the finals. There was dicey weather during qualifying and it was even worse today. The weather was too gnarly and dangerous to compete in."
Sadowski-Synnott said "I hurt my head, and got a slight concussion - I'm out for a few days.
"I was actually very stoked on my qualifying run. I did a wildcat out of the rails like I've never done before... I only learnt it the other day.
"I was hoping to put a better run down in finals, like in X-Games, but because of weather and my injury things didn't work out.
"It doesn't matter the size of the event - you should always be trying new things and progressing."
Sadowski-Synnott won silver at the world champs two years ago, took bronze in the big air competition in last year's Winter Olympics in South Korea, and became the first Kiwi snowboarder to win X-Games gold last month.
Her latest medal was hard to rate against her other achievements, she said.
"It's hard to compare...it feels pretty surreal now. I don't know how to compare it to everything else. It's definitely one for the books."
"After the Olympics and X-games more people are watching out for me which is kind of scary but also exciting at the same time," she said.
However, she won't be able to return home for the Halberg Awards, New Zealand's premier sports awards.