Novak Djokovic is through to the fourth round of Indian Wells following a comfortable 6-2 6-3 win over Kevin Anderson in California.
The two players exchanged games at the beginning of the first set before consecutive wins allowed the world number one to gain control.
Djokovic survived break point in a long fifth game before breaking Harrison in the next to take a 4-2 lead.
The Serbian then won back-to-back games to put a shaky start behind him and claim the first set against his South African opponent.
From then on, it was business as usual for Djokovic, who took the second 6-3 after breaking in the sixth game.
He will face either Pablo Andujar or Albert Ramos, who meet in an all-Spanish third-round tie on Monday.