Novak Djokovic battles past British wild card Jacob Fearnley at Wimbledon

The seven-time champion, still wearing a knee support following his recent surgery on a torn meniscus, dropped the third set but got the job done 6-3 6-4 5-7 7-5 in exactly three hours.

"I dropped my level," admitted the Serbian. "I think I should have done some things better in the third set to finish it off.

"I think I just did enough to win there in the fourth. I was a bit lucky to really get out of trouble and not go a break down.

"Hopefully I can raise the level in the upcoming rounds."

Djokovic will face Australian Alexei Popyrin, who knocked out 30th seed Tomas Martin Etcheverry in five sets, in round three.

Another potential hurdle for Djokovic removed itself when seventh seed Hubert Hurkacz, his projected quarter-final opponent, was injured winning a point.

The 27-year-old from Poland, highly-fancied at this year's Championships, dived to make a volley during a fourth-set tie-break against Frenchman Arthur Fils and hurt his knee.

Hurkacz, who ended Roger Federer's Wimbledon career three years ago, tried to play on after having the knee strapped up but managed just two more points before retiring.

Grigor Dimitrov, the Bulgarian 10th seed, had to come from two sets down to beat Chinese teenager Shang Juncheng, a player 14 years his junior, in five.

American 13th seed Taylor Fritz needed four sets to see off the stubborn Arthur Rinderknech and another Frenchman, Gael Monfils, won the battle of the veterans 7-6 (5) 6-4 7-6 (3) with Stan Wawrinka.

Australian ninth seed Alex De Minaur beat Spain's Jaume Munar in straight sets while Ben Shelton, the 14th seed from America, won his second five-setter of the week, 10-7 in a fifth-set tie-break, to edge past South African Lloyd Harris.

In the final match on Court One, fourth seed Alexander Zverev underlined his title credentials with a 6-2 6-1 6-4 stroll past Marcos Giron.

But 11th seed Stefanos Tsitsipas was a second-round casualty, losing in four sets to Finland's Emil Ruusuvuori.