 Complete the following phrase:  A former English Amateur Championship and World Amateur Championship finalist, Johnson turned professional in 1979, and after several years as an unranked player, reached the final of the 1983 Professional Players Tournament, where he narrowly lost 89 to Tony Knowles. In 1986, as a massive underdog, he defeated Steve Davis 1812 to win the 1986 World Snooker Championship. The 