Aussie Jordan Thompson downs Grigor Dimitrov at Miami Open

Jordan Thompson's giant-killing run at the ATP Tour's Miami Open has continued with a third-round win over Bulgarian star Grigor Dimitrov.

Australian world No.77 Thompson beat the 24th seed 7-5 7-5 to advance to the last 16 at the Masters 1000 series tournament, having already dispatched 10th seed Karen Khachanov in the previous round.

Thompson will play big-serving Kevin Anderson for a spot in the quarter-finals after the South African sixth seed conquered Portugal's Joao Sousa 6-4 7-6 (8-6).

Roger Federer was forced to battle early before overcoming Serbia's Filip Krajinovic 7-5 6-3 in his third round match.

Next up for Federer is a clash with either American qualifier Reilly Opelka or Russian Daniil Medvedev.