It is business as usual for Kerber, Djokovic in Miami

Bertens dominated the world number three in the opening set, but the 24-year-old became unwell early in the second set and was forced to take a medical timeout. She eventually retired with an illness in the final set to hand Kerber a 1-6 6-2 3-0 win on another steamy day in south Florida. 

Later, five-time champion Novak Djokovic overcame a first-set spill to beat unseeded Joao Sousa of Portugal 6-4 6-1 in the third round. 

The world number one fell on his left side while hitting a forehand on the baseline and his shot went into the net to allow Sousa to pull even at 4-4. But Djokovic was not injured and he dusted himself off and won eight out of the next nine games in a 77-minute match. 

The Serb is vying to match Andre Agassi’s tournament record of six wins in Key Biscayne. “That first set came down to a few points,” said Djokovic after improving to 24-1 in 2016.