Smirnov was the Australian junior champion in 2014 and won the Australian Grand Prix in 2015. He has represented his country in the Chess Olympiad in 2014 in Tromsø, Norway and in 2016 in Baku, Azerbaijan. In the Tromsø Chess Olympiad he was undefeated playing on board 5 and scored 7½/9 points. In the Baku Chess Olympiad he was undefeated again, this time on board 4 scoring 8½/10 points. He also achieved 20-game norm for the title Grandmaster.