Ilia was born in Belarus, where he was certified as a chess trainer by the Belarussian State Institute of Physical Culture. In 1994, having won the Belarussian Championship, he immigrated to Israel, subsequently representing that country in various Olympiads and other international competitions. His tournament successes include winning the First League of the USSR Championship in 1987 and 1989 as well as winning the Israeli Championship for three consecutive years (1992-1994). Known for his uncompromising, tactical play, Ilia attributes his sharp style to the influence of such players as Mikhail Tal and Leonid Stein. He reached his peak rating of 2702 FIDE in July 2001.