Following his world championship victory, Thorburn bought a house in England with the intention of spending more time in Britain. He won the Canadian Open for a third successive year in 1980, defeating Griffiths 17–10 in the final, and was part of the Canada Team that reached the final of the 1980 World Challenge Cup, where they lost 5–8 to Wales. He led Higgins 5–1 in the semi-final of the 1981 Masters, but lost the match 5–6. At the 1981 World Championship, as defending champion, he reached the semi-final where he lost 10–16 to Steve Davis. Following a 4–10 loss to Jimmy White in the first round of the 1982 World Snooker Championship, Thorburn decided to return to Canada. Thorburn had been number two in the &lt;a href="Snooker%20world%20rankings%201980/1981"&gt;1980/1981 world rankings&lt;/a&gt;, and reached number one in the &lt;a href="Snooker%20world%20rankings%201981/1982"&gt;1981/1982 rankings&lt;/a&gt;. He won the 1983 Masters, recovering from 2–5 behind against Charlton to win 6–5 in the semi-final, and defeating Ray Reardon 9–7 in the final.