Second seed Rafael Nadal through to the fourth round of Miami Masters . The three-time runner-up at the U.S. hard-court event beat Czech Radek Stepanek . No . 4 Philipp Kohlschreiber 6-4 7-6 , and will next face another German -- No . 19 Florian Mayer . Andy Murray will face American John Isner in a rematch from last year's Wimbledon final. Murray handed a walkover after opponent Milos Raonic had to withdraw through injury .
Second seed Rafael Nadal through to the fourth round of Miami Masters . The three-time runner-up at the U.S. hard-court event beat Czech Radek Stepanek . No . 4 Andy Murray will face American John Isner in a rematch from last year's Wimbledon final. Murray handed a walkover after opponent Milos Raonic had to withdraw through injury .