Canada's Mark McMorris owned first place in the event, taking place live early Sunday morning and in primetime Saturday night for American TV audiences, with a second-run score of 85.20. But Gerard's final run, capped by a triple cork 1440, moved McMorris off the top of the podium.
McMorris's fellow Canadian, Max Parrot, the last snowboarder of the day, then bumped him to third with a brilliant final run that netted a score of 86.00, falling just short of the gold. McMorris couldn't better his second-run score of 85.20 after not playing it safe on his final run by trying to stick a 1620 off the final jump.
In addition to topping Parrot and McMorris, Gerard also beat Norway's Staale Sandbeck (81.01) and New Zealand's Carlos Garcia Knight (78.60) to top the podium. His slopestyle title marks a triumphant start to his Olympic career, which began in Pyeongchang for this year's Winter Games, and also makes him the youngest American to medal in a snowboard event at the Olympics. He's also the second successive American to win the event, which made its Olympic debut in 2014. Sage Kotsenburg claimed the top spot in Sochi.
After struggling with the second of three large jumps on the course, Gerard, who is listed at a full 117 pounds, finally stuck the switch 1260 he had failed to land in his previous two trips down the course. He then loaded up and stomped a triple cork 1440 on the last jump, cleanly completing four rotations and landing perfectly without scrubbing even a glove.