Kurnosov started playing chess at age 6, and became a grandmaster in 2003, at the age of 18. He had an aggressive playing style known for complex middlegame positions, and the King's Indian Defence was one of his favourite opening systems.
Kurnosov's impressive tournament victories across the globe include Hastings Masters (2008-2009), the Arctic Challenge in Tromsø (2009), and the 53rd and 54th editions of the Komi Republic Championship in Syktyvkar (2003 and 2004). He also won the rapid event in the 2011 ACP Golden Classic in Amsterdam and took part in the Chess World Cup in 2005, 2007 and 2009.
Outside his professional career, Kurnosov was married, had a daughter and lived in Chelyabinsk - a city known as "The Gateway to Siberia".