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.

But, ominously for the rest of the men’s draw, Djokovic looked more like the player who has not lost a match here since 2017 as he effortlessly saw off world number 79 Kokkinakis 6-1 6-4 6-2.

Novak Djokovic was in imperious form (Steven Paston/PA)

The 35-year-old is vying for a fourth straight title and to move level with Pete Sampras on seven, and within one of men’s record-holder Roger Federer, and on this form it is hard to see anyone stopping him.

After completing victory in exactly two hours, Djokovic said: “I’m happy with my performance today. A really high-quality performance.

“I must say I’m quite pleased with the way I’ve raised the level of tennis in two days.

“Hopefully I can keep that trajectory, just thinking about the next challenge and hope things will get better as the tournament goes on.”

Forgetful Frenchman Ugo Humbert left his rackets behind ahead of his match with Casper Ruud.

Despite a rain delay of more than an hour and a half, the 24-year-old world number 112 still managed to arrive on Court Two without the tools of his trade.

But after sending someone to the locker room to fetch them, Humbert remembered how to play as he knocked out third seed Ruud.

Norwegian Ruud, the French Open runner-up, is no fan of the grass courts and bowed out 3-6 6-2 7-5 6-4.