Australia won a World Cup game for only the third time in their history with a dogged 1-0 victory over Tunisia on Saturday to revive their last-16 hopes, and make the knock-out stages a distant dream for the North African side. Striker Mitch Duke scored the only goal of a tight game with a clever header in the first half and Australia then desperately held on to silence Tunisia’s spirited fans. Australia sit second in Group D with three points from two games, having been well-beaten 4-1 by holders France in their tournament-opener. The Socceroos face Denmark — who play France later Saturday -…