The anticipation was building at Wimbledon's Centre Court. The showdown between Australia's Nick Kyrgios and the US's Brandon Nakashima was only minutes away.

The crowd had just two questions about yesterday afternoon's match. One was whether 20-year-old Nakashima, playing in only his second Wimbledon, would produce an upset. The other was whether Kyrgios would repeat the behaviour that shocked fans watching his previous matches.

He was only 12 minutes into the tournament when he had his first tantrum, hitting a ball out of the court after losing a service game to Britain's Paul Jubb. He then started ranting at the umpire about the noise from the crowd. Later, when a female line judgeAn official who watches the lines to rule on whether the ball is in or out. Increasingly, electronic eyes are being used instead. reported him to the umpire, he responded by calling her "a snitch". He also spat in the direction of a hecklingShouting criticism, usually as a member of a crowd. spectator.

But that was nothing compared to the furious encounter between Kyrgios and the fourth seed, Greece's Stefanos Tsitsipas, on Saturday. One former player, Jeff Tarango, said that it was the closest thing he had seen to a fist fight on court. Kyrgios, he declared, was "a volcano waiting to happen".

Kyrgios, who has been nicknamed "the third commentator", kept up a constant stream of criticism aimed at the match officials. "Get a new referee!" he demanded when the umpire overruled a line call. He also wound Tsitsipas up by serving before his opponent was ready - on one occasion humiliating him with an underarm serveAllowed in professional tennis, but sometimes considered sneaky..

"The tennis became secondary and it became almost impossible for Stefanos Tsitsipas to play," said another former player, John Lloyd. "Kyrgios was basically trying to disrupt his opponent's game."

Then, when Tsitsipas became so frustrated that he hit a ball into the crowd, Kyrgios attacked the umpire for not cracking down on bad behaviour. In the end both players were fined - but Krygios took the match. Tsitsipas afterwards called him a "bully" with an "evil side".

Kyrgios has now paid almost £700,000 in fines in his career, including the largest one ever given in tennis - £113,000. That was for swearing at the umpire and smashing two racquets after losing a match in CincinattiA city in the US state of Ohio..

Other incidents include hurling a chair across the court at the Italian Open in 2019, and making obscene remarks about an opponent's girlfriend during a match in 2015. He has twice been booed for "tanking", once at Wimbledon and once in Shanghai. In 2016 he was left out of Australia's Olympic squad because of his behaviour.

Yet everyone agrees that he is a hugely talented player. Yesterday, he proved it by beating Nakashima to reach the last eight. And some feel that as with John McEnroeAn American player who won Wimbledon four times in the 1980s. He is now a BBC commentator. - Wimbledon's original bad boyHe was famous for losing his temper, and once shouting at the umpire: "You cannot be serious!" - the passion he brings to the game is something to be admired.

"Yes, he is dangerous; yes, he is unstable... no, he is not nice," wrote Owen Slot in The Times. "But there is place for dramatic tension in sport: it's called entertainment."

Slot's colleague Alyson Rudd was less forgiving. "He attracts headlines and comment... but he takes it too far and has become a hypocrite."

Yes: We need them to shake up the established order of things and make new developments possible. Wimbledon is famous for being stuffily traditional and will benefit from the buzz Kyrgios brings.

No: Institutions like Wimbledon are admired because they have developed in a civilised way over a long period of time. They are the product of careful thought which ought to be respected.

Or... To call people like Kyrgios rebels is to flatter them. He is not out to change the world - he is just a spoilt brat with no manners who behaves disgracefully when things do not go his way.

Line judge - An official who watches the lines to rule on whether the ball is in or out. Increasingly, electronic eyes are being used instead.

Heckling - Shouting criticism, usually as a member of a crowd.

Underarm serve - Allowed in professional tennis, but sometimes considered sneaky.

Cincinatti - A city in the US state of Ohio.

John McEnroe - An American player who won Wimbledon four times in the 1980s. He is now a BBC commentator.

Bad boy - He was famous for losing his temper, and once shouting at the umpire: "You cannot be serious!"