Career
Guan made his first appearance in the main singles draw of a Grand Slam at the 1981 Australian Open, where he lost in the opening round to Pat Du Pré, in five sets. This equaled his best Grand Slam performance, as he also reached the quarter-finals in the doubles at the 1980 Australian Open, partnering Ernie Ewart. His best singles effort came when he made the third round at the 1982 Australian Open.
On the Grand Prix tennis circuit, Guan made one doubles final, at the 1979 Australian Hard Court Tennis Championships with Philosophy Davies.
They lost to John James and Chris Kachel. He was a singles quarter-finalist at Brisbane"s South Pacific Tennis Classic in 1981.