Reira Iwabuchi missed out on becoming the youngest ever female Japanese medalist at the Winter Olympics as the teenager finished fourth in the snowboarding women's big air of the Pyeongchang Games on Thursday.

At 16 years and two months, Iwabuchi would have rewritten the record set by figure skater Mao Asada at 19 years, five months at the 2010 Vancouver Olympics had she made it to the podium.

After the first two runs, Iwabuchi was 10 points behind third place and fellow 16-year-old Zoi Sadowski Synnott of New Zealand, who fell on her third run to give Iwabuchi a shot at the podium.

But Iwabuchi botched her landing, throwing Sadowski Synnott a lifeline. Iwabuchi finished with 147.50 points after a 79.75 in the first run and 67.75 in the second.

"The results don't lie. I just wasn't good enough to take that one final step," Iwabuchi said. "I have to learn to finish things off and that's where I'm coming up short now. I wasn't good enough."

Iwabuchi's compatriots Yuka Fujimori (122.75) and Miyabi Onitsuka (119.00) were seventh and eighth, respectively, in a field of 12.

Austria's Anna Gasser scored 96.00 on her final run for a 185.00 total to become the inaugural women's big air gold medalist. Jamie Anderson of the United States was runner-up with 177.25 points, coming up short in capping a double with her slopestyle title.

In the final where each rider gets three runs, the lowest score is dropped and the two highest scores are combined to get the total.

The pint-sized 1.49-meter Iwabuchi said she managed to hold her nerves, pointing out it was the execution that kept her away from a medal. But after the competition, the first-year high school student from Iwate Prefecture broke down in tears upon seeing her family in the stands.

Grounded beyond her years, Iwabuchi was already looking forward to Beijing 2022.

"I wasn't too nervous. I was right where I needed to be mentally, and had fun riding out there today," Iwabuchi said.

"To have another opportunity at the Olympics in four years, I need more spin and I think the competition will be even tougher than it is now. I've got to be much better."