The 30-year-old, the oldest snowboarder to make the final, held off a fleet of prodigies to claim victory, most notable of these being the 20-year-old from New Zealand, who had already won the gold medal in slopestyle in the Chinese capital.

In qualification, the Kiwi put down the mark to beat by finishing first in front of Japanese youngsters Kokomo Murase and Reira Iwabuchi.

In the final, Gasser stringed together two strong opening runs to all but ensure she would make the podium, with marks of 90.00 and 86.75 points, respectively.

Sadowski Synnott scored 93.25 and 83.75, meaning she had the lead by just 0.25 points, the finest margin of scoring in freestyle snowboard and ensuring run would be a test of nerve.

Gasser went first and sent the crowd wild when she landed a cab double corkscrew 1260 melon, the first time she had pulled the trick out during a competition.

The Austrian was rewarded with a score of 95.50 points - the best of the competition for a combined 185.50.

Pressure was on Sadowski Synnott, who had to get a mark of 92.00 points to win the gold medal.

She attempted a backside double corkscrew 1260 indy but failed to land it and finished with 177.00 points, meaning Gasser became a two-time big air Olympic champion.

Gasser claimed she had not bothered about what colour of medal she got, but was more interested in progressing snowboarding.

"I didn't care about the result, I cared about the snowboarding," she said to insidethegames.

"I love progressing and getting pushed by all these amazing young riders. 

"I just wanted to show the big tricks. 

"I wanted to show the last trick and I didn't care about the result.

"I didn't care about the 0.25."

Murase made up for disappointment in slopestyle to take the bronze medal with a score of 171.50 points, but it could have easily been her team-mate on the podium after Iwabuchi nearly-landed an unprecedented frontside triple corkscrew 1260 underflip.

Iwabuchi pulled out the move to the surprise of the crowd, but landed slightly on her tail on the landing, destabilising her and causing fall after what looked like a sound run.

She finished fourth behind Murase.

"We saw it from the top and we were freaking out," added Gasser on Iwabuchi's last attempt.

"She chose progression and I admire that. 

"I have so much respect for her for that."

China's 17-year-old Su Yiming claimed his first Olympic gold medal by winning the men's event in the afternoon, with no-one able to match his first two routines for a combined score of 182.50 points.

It followed on from silver in the slopestyle, in which he controversially lost to Canadian Max Parrot over an alleged judging fault in the scoring.

The teenager, who turns 18 on Friday (February 18), scored 89.50 and 93.00 points, as many of his challengers failed to put two strong runs together.

Only six of the 12 had two decent attempts, the second-best of these being Mons Roisland from Norway, who took the silver by just 1.5 points with a score of 171.75.

Parrot took the bronze medal in front of Hiroaki Kunitake of Japan and American Red Gerard, who both occupied third before Roisland and the Canadian's final efforts.

Chris Corning of the United States and Takeru Otsuka of Japan both had high scores over 90 points that put them in contention for a medal, but could not get near that in their final attempts.

Otsuka's 95.00 was the highest score in the event after he landed a cab triple corkcrew 1800 indy.

Parrot scored 94.00 points for the same trick straight after the Japanese snowboarder, aiding him to the bronze medal.