Novak Djokovic left fans and viewers scratching their head at the All England Club on Monday as he went on a bizarre rant, accusing Wimbledon fans of 'disrespect' after reaching a 60th Grand Slam quarter-final.

Djokovic, the world No 2 and seven-time champion at Wimbledon, made it clear he was not happy with the behaviour of supporters during his 6-3, 6-4, 6-2 win over 15th-ranked Holger Rune.

Djokovic took exception to constant chants of 'Rune' throughout the match at Centre Court, which the Serb interpreted as boos directed at him.

'To all the fans that have had respect and stayed here tonight, I thank you from the bottom of my heart and I appreciate it,' said a seemingly angry Djokovic.

'And to all those people that have chosen to disrespect the player – in this case me – have a goooooooood night,' he added, mocking the chants of 'Ruuuuune'.

The interviewer then informed Djokovic that fans were shouting 'Rune' rather than 'boo', but the Serbian star was having none of it.

'They were [booing]. They were. I am not accepting it. No, no, no. I know they were cheering for Rune but thats an excuse to also boo,' he said.

'Listen, I have been on the tour for more than 20 years. I know all the tricks, I know how it works. I focus on the respectful people that pay for the ticket, and love tennis and appreciate the players.

'I have played in much more hostile environments, trust me – you guys cant touch me.'

Later in the post-match presser, Djokovic said there is not much organisers can do to check crowd behaviour.

“Look, I don’t know what Wimbledon can really do about it. I mean, in those particular moments when it happens, the crowd paid their tickets. They have the right to be there and cheer the way they want to cheer. That’s absolutely something they choose – how they behave or how they choose to support the player is really up to them,” Djokovic said.

“Yes, you could argue maybe a chair umpire or whoever can step in in certain moments and calm them down, but there’s not much you can do. You’re not going to take out the whole section of the crowd or stadium because they’re misbehaving.”

The strange turn of events took some sheen off his impressive win. Djokovic, who dropped sets in the second and third rounds, was expected to be tested by Rune, but instead gave the young Dane a harsh lesson over two hours.

The Serb, 37, still wearing a knee support on his right knee after surgery last month, did not drop a single point in the opening three games against his opponent.

He engineered a single break in the second set before two more breaks in the third set sealed a quarter-final against Australian ninth seed Alex de Minaur.

In another pulsating last-16 match, Alexander Zverev turned up on court wearing a protective support around his leg after falling awkwardly during his previous match.

That did not stop the German trading brutal blows with Taylor Fritz for three-and-a-half hours before he fell to a 4-6, 6-7, 6-4, 7-6, 6-3 defeat after he was finally broken for the first time at this years championships having chalked up 56 successive holds of serve.

Zverev fired down 19 aces, produced 55 winners and even won the longest rally in the contest which dragged on for 21 shots. But by the end of it, the German said he had been playing 'on one leg'.

'It was fairly obvious that I wasnt 100 per cent today, right?' Zverev asked reporters before elaborating that an MRI scan had shown that he had a tear in his knee capsule as well as bone bruising.