200 metres Butterfly, Men

West German Michael Groß was the clear favorite. He had won the event at the 1982 World Championships, and had set the world record to win the 1983 European Championships, with 1:57.05. By contrast, Jon Sieben had a best time of 2:01.17 coming into the Olympics, which he had done at the Australian Trials in February, and was a long shot to even make the final. When this event started, Groß had already won the 100 fly and the 200 freestyle, and the only question mark seemed to be who would win the other medals, with Pablo Morales (USA) and Venezuela’s Rafael Vidal seemingly being the main challengers. But Sieben surprised in qualifying with 1:59.63 to move on to the final.

The final started as expected as Groß went out fast, trailed early by Vidal. Morales made his move at 100 metres. Sieben was out in lane six, unwatched by the crowd and the other swimmers, but by the final turn he had moved to Vidal’s shoulder, who was in lane five. In the last 25 metres it was very close, with all four swimmers coming to the wall almost together and no one was certain who had won. In one of the biggest upsets in Olympic swimming history, it was Jon Sieben, who said later, “I only knew I’d won when I turned around and saw on the board.” Sieben finished in a world record 1:57.04, 1/100th of a second ahead of Groß’s mark, with Groß in second, Vidal and third, and Morales pushed off the podium despite swimming 1:57.75.