World No . 1 Novak Djokovic is on course for third successive Miami title . Serbian will next face 15th seed Tommy Haas in the last 16 of hard - court event . Maria Sharapova , three times a runner - up at Key Biscayne , also through to round four . Indian Wells winner will next play Czech world No . 22 Novak Djokovic and Maria Sharapova progressed to the fourth round of the Miami Masters on Sunday , neither impressed with their form as they battled windy , hot conditions . Sandra Zakopalova .
World No . 1 Novak Djokovic is on course for third successive Miami title . Serbian will next face 15th seed Tommy Haas in the last 16 of hard - court event . Maria Sharapova , three times a runner - up at Key Biscayne , also through to round four . Indian Wells winner will next play Czech world No . 22 Sandra Zakopalova .