Novak Djokovic is into the US Open semi-finals with a straight sets victory over the world number 55 John Millman from Australia. Novak who as won the championship twice at Flushing Meadows won the match 6-3 6-4 6-4 and will now face Kei Nishikori from Japan on Friday. Nishikori overcame seventh seed big serving Marin Cilic in a epic five-set match 2-6 6-4 7-6 4-6 6-4.