His win is the first gold medal for the United States.
Red Gerard's Amazing Win
The teenager, who comes from Silverthorne in Colorado, moved from 11th place on a ranking of 12 finalists in a surprise move that placed him above Canadians Max Parrot and Mark McMorris.
The crowd at the Phoenix Snow Park did not expect his win and erupted when it was clear that he had won the competition with an 87.16 final run.
The Rise Of A New Snowboarding Champion
Gerard, who has now been given the name Peter Pan, was stunned by his Sunday feat. The Denver Post reports that he said the words "Oh. My. God" in the wake of his win, as he looked at the scoreboard with his name at the top.
His father, Conrad Gerard, said his son was oblivious of the scale of the competition before his victory.
His big win has broken some records. Red "Peter Pan" Gerard did not only give the US its first gold medal at the PyeongChang Olympics. He also becomes the youngest snowboarding gold medalist ever.
Red said he started the competition with a simple desire to land a run after his first two turned out badly. He described his amazing win for his country as awesome.