Leach faced a tough draw in the 1949 World Championships in Stockholm where he beat Ferenc Sidó, Dick Miles, and Ferenc Soos en route to the final. There he faced two-time singles World Champion Váňa, whom he had never beaten. Leach won the first set 21–19, but dropped the second 11–21. He rallied to win the third set 21–17, but Váňa took the fourth set 21–14. Leach emerged victorious, winning the fifth set 21–16. The win made him just the second British-born player to win a singles World Title. He also made the semi-finals of mixed doubles with Margaret Franks that year, winning a bronze medal.