Bonnyrigg has a fierce rivalry with the Croatian backed Sydney United. The two clubs first met in the state leagues in the late 1970s with then Sydney Croatia dominating almost most of the games between the two clubs. Avala and Croatia met in the Ampol Cup Semi Final in 1977 in which Avala defeated Croatia one goal to nil. The last time the two clubs would meet would be in 1983 with Croatia being promoted to the National Soccer League and Avala remaining in the State leagues.