After a few years of competing in local and PGA Tour events, Fleck decided to play full-time on the Tour for two years. Within six months, Fleck had his first win — on the biggest stage in men's professional golf — at the 1955 U.S. Open. Fleck won an 18-hole Sunday playoff by three strokes over his idol, Ben Hogan, at the Olympic Club in San Francisco. His first round deficit of nine strokes (behind Tommy Bolt), was the greatest number overcome by a U.S. Open winner. The following year he resigned his job as a municipal club pro in Davenport and moved to the Detroit area in October 1956.