Australian No 1 clashes with world No 1 in mixed-teams quarter-final Rinky Hijikata and Jordan Thompson win at Brisbane warm-up Alex de Minaur says he's looking forward to testing himself against the "GOAT" Novak Djokovic in Wednesday night's United Cup quarter-final against Serbia in Perth. The men's singles match-up between de Minaur and Djokovic looms as one of the biggest clashes of the $US10 million ($A15 million) mixed-teams event.