Olympics: Djokovic defeats Nishikori to enter semi-finals
Djokovic will continue his quest for Olympic glory and a calendar slam against either of Germany's Alexander Zverev or France's Jeremy Chardy in the semi-final.Meanwhile, Russian second seed Daniil Medvedev crashed out of the quarter-finals after a 6-2, 7-6(5) loss to Spain's Pablo Carreno Busta in a clash which ran for an hour and 43 minutes.Busta next faces Karen Khachanov, who was made to work hard for a 7-6(4), 4-6, 6-3 win over France's Ugo Humbert in two hours and 34 minutes.
--IANS nr/kh