World number one Novak Djokovic returned to winning ways with a straight-set victory over Australian Bernard Tomic to reach the Miami Open third round. Serbia’s Djokovic, who lost in the third round at Indian Wells last week, beat Tomic 7-6 (7-2) 6-2. The 31-year-old is aiming for a record seventh title in Miami and faces Argentina’s Federico Delbonis next. Britain’s …