Wimbledon: Nick Kyrgios and Stefanos Tsitsipas argue at All England Club

The on-court "circus" between Nick Kyrgios and Stefanos Tsitsipas spilled into the Wimbledon media interview room as the Australian denied his opponent's claim that he was "a bully" who could be "evil".

Kyrgios beat Greek fourth seed Tsitsipas in a heated four-set thriller which he described as a "rollercoaster".

A combustible atmosphere saw Tsitsipas aim several shots at his former doubles partner and also receive a warning for hitting a ball into the crowd and nearly striking a spectator.

Kyrgios, 27, insisted his opponent should have been defaulted for the incident, claiming the ball hit the fan on the head, although television replays suggested otherwise.

Tsitsipas had started to lose his cool towards the end of the second set after Kyrgios repeatedly berated chair umpire Damien Dumusois.

"It felt kind of a circus, in a way. We're there to play tennis," said the 23-year-old Greek.

Kyrgios began mouthing off at Dumusois over a line call, labelling him a "disgrace" at one point in the long-running verbal exchanges, and was later given a warning after twice being reported by line judges for swearing.

The drama continued into the third set as Tsitsipas received a point penalty for responding to an underarm serve by angrily smacking a forehand, which he said was "aimed" at Kyrgios' body, into the stadium scoreboard.

At that point, it felt the match was teetering towards disqualification for one of them.

Things settled down somewhat in the fourth set, and Kyrgios eventually clinched victory on his second match point in a frenzied atmosphere under the Court One floodlights.

The pair shared a brief handshake at the net but the heat returned when they discussed the match with journalists.

"I would be pretty upset if I lost to someone two weeks in a row as well," said Kyrgios, who also beat Tsitsipas in Halle last month and now leads 4-1 in their head-to-head.

"Maybe he should figure out how to beat me a couple more times first."

Tsitsipas was the first one into the post-match interview room at the All England Club and, after a measured start, began to unload.

The Greek described Kyrgios' chuntering as "constant bullying", despite the Australian having aimed his frustrations at umpire Dumusois and not his opponent.

"He bullies the opponents," said Tsitsipas. "He was probably a bully at school himself. I don't like bullies. I don't like people that put other people down.

"He has some good traits in his character, as well. But he also has a very evil side to him, which if it's exposed, it can really do a lot of harm and bad to the people around him."

When those accusations were relayed to him by a reporter shortly afterwards, Kyrgios said he was "not sure" how he had bullied Tsitsipas.

"He was the one hitting balls at me, he was the one that hit a spectator, he was the one that smacked it out of the stadium," responded the world number 40.

"I didn't do anything.

"Apart from me just going back and forth to the umpire for a bit, I did nothing towards Stefanos that was disrespectful, I don't think. I was not drilling him with balls."

In his on-court interview, Kyrgios did say he still "loves" Tsitsipas, with whom he played doubles at Washington in 2019.

But in the news conference he added he was not going on court to "be his friend".

"We're not cut from the same cloth. I go up against guys who are true competitors," said Kyrgios.

"If he's affected by that today, then that's what's holding him back.

"If someone can just do that and that's going to throw him off his game like that. I just think it's soft."