[2] His early trainers in New Zealand were Bruce Wheeler[3] and Ewen Green,[4] followed by Darryl Johansen after Cheng arrived in Australia.

He finished tied for third place in the Under 10 division of the World Youth Chess Championships in 2007, the year he and his family moved to Melbourne, Australia.

[5] In November 2009, Cheng transferred national federations from New Zealand to Australia[6] and won the Under 12 title at the World Youth Championships in Kemer, Turkey.

[12] In December 2019, Cheng won the Australian Young Masters tournament with a perfect 9/9 score, ahead of top seed Norwegian Grandmaster Frode Urkedal.

He was the first Australian in history to win a game in the World Cup[citation needed] after defeating Vahap Şanal in the rapid tiebreaks.