Novak Djokovic hits form in straight-sets coast past Thanasi Kokkinakis

Novak Djokovic beat Thanasi Kokkinakis (Steven Paston/PA)

Novak Djokovic fired a warning to his Wimbledon title rivals by easing past Australian Thanasi Kokkinakis with a flawless display, and then vowing to get even better.

The defending champion had been unconvincing in his 6-3 3-6 6-3 6-4 victory over Korean Kwon Soon-woo in what was his first match on grass since last year’s final.