Sonny Schönbächler first appeared on the international freestyle skiing scene in 1984 World Cup events and debuted at the World Championships in 1986, where he was 10th in the aerials. He was 16th at the 1989 edition and, in-between, participated in the aerials demonstration event at the 1988 Winter Olympics, where he was 6th among 14 participants. The event earned demonstration status again at the 1992 Games, where Schönbächler finished 15th, and then became an official Olympic sport in 1994. There was nothing that year to suggest that Schönbächler was a medal contender, particularly as he had come out of retirement to compete, but he ended up as the surprise winner of the event, managing to recover from tenth place in the qualification round. He returned to retirement after the Games, having accrued only seven podium placements in over a decade at the World Cup, none of which were first-place finishes, despite his Olympic gold medal-winning performance. He later founded the Mettmenstetten ski training facility and was also an active surfer.