by Dave JAMES Agence France-Presse NEW YORK, United States (AFP) — Novak Djokovic believes that the man who lifts the US Open trophy on Sunday will have truly earned the mantle of champion, describing the hot and steamy 2018 tournament as the “toughest” he has encountered. Djokovic, the winner in 2011 and 2015, faces Kei Nishikori in Friday’s semi-finals, his 11th successive appearance in the last-four. An eighth final is within reach and to achieve […]