Cape Town — South African tennis star Kevin Anderson has reached the fourth round of the Miami Open after a straight-sets win over Portugal's Joao Sousa .
The sixth-seeded Anderson hit 13 aces in a 6-4, 7-6 (8/6) victory.
Anderson is playing in only his second tournament of the season, after losing in the second round of the Australian Open to American Frances Tiafoe.
He withdrew from four events because of a persistent right elbow injury.
Anderson will next meet Australian Jordan Thompson , who upset 24th seed Grigor Dimitrov 7-5, 7-5 to make the fourth round of an ATP Masters 1000 event for the first time.
Anderson beat Thompson 6-2, 6-4 in their only previous meeting in Chengdu, Chine in 2016.
Results on Monday from the Miami Open WTA/ATP Masters hardcourt tournament (x-denotes seeds):
Kevin Anderson (RSA x6) bt Joao Sousa (POR) 6-4, 7-6 (8/6)
Jordan Thompson (AUS) bt Grigor Dimitrov (BUL x24) 7-5, 7-5
Daniil Medvedev (RUS x13) bt Reilly Opelka (USA) 7-6 (7/5), 6-7 (5/7), 7-6 (7/0)
Roger Federer (SUI x4) bt Filip Krajinovic (SRB) 7-5, 6-3
Denis Shapovalov (CAN x20) bt Andrey Rublev (RUS) 6-3, 7-6 (7/5)
David Goffin (BEL x18) bt Marco Cecchinato (ITA x14) 6-4, 6-4
Hsieh Su-Wei (TPE x27) bt Caroline Wozniacki (DEN x13) 6-3, 6-7 (0/7), 6-2
Anett Kontaveit (EST x21) bt Bianca Andreescu (CAN) 6-1, 2-0 (ret)
Petra Kvitova (CZE x3) bt Caroline Garcia (FRA x19) 6-3, 6-3
Ashleigh Barty (AUS x12) bt Kiki Bertens (NED x7) 4-6, 6-3, 6-2
Simona Halep (ROM x2) bt Venus Williams (USA) 6-3, 6-3
Wang Qiang (CHN) bt Wang Yafan (CHN) 7-5, 6-4