Defending champion John Isner reached the Miami Open quarter-finals.
Djokovic dismisses any suggestion of friction with Federer and Nadal as tennis politics spilled over to the Miami Open.
Verdasco got into a Twitter spat with Australian Kyrgios over a wish for Spaniard to lose.
Venus Williams fends off three match points before outlasting Dutch 29th seed Bertens.
Indian Wells champion Naomi Osaka defeated 23-times grand slam champion Serena Williams 6-3 6-2 in the Miami Open.