John Isner reached the semifinals of the Miami Open after easily beating fourth-seeded Kei Nishikori of Japan 6-4 , 6-3 on Thursday . The 6-foot-10 , hard-serving Isner is the first American man to make the semifinals in Miami since 2011 . He 'll next meet either world No . 1 Novak Djokovic or David Ferrer on Friday night . Isner won the final eight points of the first set , breaking Nishikori at love to end it . He then ran out to a 3-0 lead in the second set and never faced serious trouble . Big serving John Isner became the first American to reach the semi finals in Miami since 2011 . Kei Nishikori could not cope with Isner 's power play in a straight sets 6-4 , 6-3 defeat . Nishikori never had a break chance Thursday , and Isner has n't been broken in the tournament . Meanwhile , Andy Murray will face not one but two of his former team when he meets Tomas Berdych in the other semi final in Key Biscayne . His former fitness coach Jez Green has followed his once close friend and assistant coach Dani Vallverdu , to join the Czech world No 9 . Sparks flew when the pair met in this year 's Australian Open semi-final , which Murray eventually won in four sets . There will be no love lost when Andy Murray takes on Tomas Berdych in the other semi final . Even mild mannered Kim Sears was captured uttering expletives in the Czech 's direction at Australian Open .
John Isner will play either Novak Djokovic or David Ferrer in 2011 . He became the first American to reach Miami Open semi final since the last four . Kei Nishikori could not handle Isner 's serve in a 6-4 , 6-3 defeat .