Novak Djokovic accused some of the Centre Court crowd of using a Holger Rune chant as "an excuse to boo" as his hot-and-cold relationship with Wimbledon took another turn.
Hundreds of fans greeted Rune winners, and Djokovic errors, with elongated cries of 'Ruuuuuuune' during the pair's fourth-round match on Monday.
Djokovic - a convincing 6-3 6-4 6-2 winner - felt the crowd were disrespecting him.
When on-court interviewer Rishi Persad put it to the Serb that they were supporting his opponent, Djokovic said there was more to it.
"I know they were cheering for Rune but that's an excuse to also boo," he said.
"I have been on the tour for more than 20 years. I know all the tricks."
Djokovic is attempting to win a joint record eighth Wimbledon men's title, and is a nine-time finalist at SW19.
But his relationship with the crowd has not always been serene.
After Djokovic beat Roger Federer in the 2019 final, his former coach Boris Becker said he deserved more respect from a partisan crowd who had mostly sided with his opponent.
And two years ago, Djokovic was booed after he blew a kiss to fans following his semi-final win over Briton Cameron Norrie.
On Monday, Djokovic looked unfazed for much of the match, though after taking the second set he did stare at a pocket of Rune supporters.
He also looked towards chanting fans when standing by the microphone as he waited for his on-court interview.
"I played in much more hostile environments, trust me - you guys can't touch me," he said.
"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."
Rune, for his part, thought it was clear what the fans were doing.
"If you don't know what was happening, probably it sounded like 'boo'. But if we all know what happened, it was my name," said the 21-year-old.
"If he didn't remember, it could probably sound different for him. I don't think it played a massive part in the match."
Djokovic, who faces Australian ninth seed Alex de Minaur in the quarter-finals, appeared to have seen the funny side of things by the end of his interview.
He signed off by saying: "To all those people that have chosen to disrespect the player - in this case me - have a goooooooood night."
But in a later interview with BBC Sport he stood by what he had said.
"When I feel a crowd is stepping over the line, I react," he said. "I don’t regret my words or actions on the court."
Djokovic's post-match comments caused quite a stir. Here's what BBC Sport's team of pundits and commentators made of his outburst.
Former Wimbledon champion Pat Cash: "There were some people that were disrespectful, took advantage that they could hide the booing. He is quite sensitive about that stuff. It's tough and I feel for him."
BBC Tennis commentator Nick Mullins: "It was one of the spiciest post-match interviews I've heard in a long time at Wimbledon. It carried some heat. It was good to hear Novak speaking from the heart."
American former world number six Chanda Rubin: "I was shocked by his reaction. Of course we know Djokovic. He likes to have a little bit of that chip on his shoulder. He wants to have something that he can dig into, get his teeth into the match."
Former GB Davis Cup captain John Lloyd: "I think he messed up without realising it. Then he dug himself a bit of a hole and he didn't know how to get out of it. This is all a big fuss over nothing."
Ex-British number one Annabel Croft: "I think for somebody as successful as he is, he's still very confused as to why he doesn't get the love of the people the way Roger Federer and Rafael Nadal did. He seems to be like a rebel with a cause and hell enjoy taking on the crowds as well as his opponent."
Former Wimbledon champion Marion Bartoli: "When you are Djokovic, you deserve to have some respect on the court. You can cheer for his opponent but it has to be done in a certain way."
BBC Sport presenter Clare Balding: "A panto villain? If they were dead silent, he would hate that too. He played exceptionally well, and played even better when he got angry. Once you rile him his standard rises."
Four-time Grand Slam champion Kim Clijsters: "Because he's mentally so good, I would have loved to see a little sarcasm, like ‘what, I didn't hear anything’. Don't waste your energy on that stuff."
