Calm in real life but demons on court - Medvedev runs out of chances
Watch: Medvedev disqualified after striking fan with ball
Daniil Medvedev once said you would need to knock on his hotel door at 6am for seven days in a row to make him angry.
On court, though, he is a far more combustible character who finally ran out of chances when he was disqualified from Monday's China Open semi-final against Novak Djokovic.
Djokovic was serving for a place in the final when the ball ricocheted off the back of the court. Medvedev swiped it into the stands, where it hit a spectator in the face.
A few minutes later the Russian was defaulted, as he had to be, under rules that bar a player from "hitting a ball dangerously or recklessly, or with negligent disregard of the consequences."
Players have got away with worse. There is sometimes anger in their actions, but it is rarely of the bulging-neck-vein variety.
It is more often a sign of irritation and petulance, with frustrations taken out on the ball with little care for the safety of officials, ball kids and the spectators who line the court.
"I can only say I'm a really calm person in life - I actually have no idea why the demons go out when I play tennis," Medvedev said at the 2019 US Open, where he was fined for snatching a towel from a ball person and making an offensive gesture to fans inside the Arthur Ashe Stadium.
"Especially when I was a junior, I had a lot of problems with my attitude.
"I was not getting defaulted, but to have a game penalty was easy."
Returning to the theme at that year's end-of-season ATP Finals, Medvedev said any bad blood soon disappears after leaving the court.
"All my temper goes away after I leave the tennis court. If I'm not happy with my practice, I step out of the court and five minutes later, I'm OK," he said.
Medvedev has made a habit of arguing with umpires and occasionally taunting the crowd
It is hard - and probably unwise - to take your eyes off Medvedev's matches, and he is very popular with the media for his engaging, reflective and humorous interviews once the dust has settled.
But he has gone too far on court on many occasions, with much of his aggression directed at umpires.
At Wimbledon in 2017, a 21-year-old Medvedev was so incensed about some of the decisions made by umpire Mariana Alves in his second-round match that he sprinkled coins at her feet as she climbed down from the chair.
He later apologised and denied he was accusing her of bias.
Two years ago, again at Wimbledon, it appeared officials were considering defaulting Medvedev for an outburst towards umpire Eva Asderaki-Moore.
Medvedev claimed he said something in Russian which was "not pleasant, but not over the line" - and, after a discussion between the umpire, supervisor and tournament referee, he escaped with a code violation for unsportsmanlike conduct.
He was fined more than £60,000 for his behaviour at the 2025 Australian Open, which included trying to destroy a net camera, and had an infamous meltdown later that year at the US Open.
On a rowdy New York night, Benjamin Bonzi had match point for a straight-set win against Medvedev in the first round when a photographer inexplicably walked on to court between his first and second serves.
Umpire Greg Allensworth awarded the Frenchman another first serve because of the delay, sparking fury from Medvedev.
Medvedev accused Allensworth of hoping to engineer a quick finish - as he gets paid by the match, rather than the hour - and there was a pause of over five minutes as he whipped up the crowd.
He did save the match point, but went on to lose in five sets before obliterating his racquet by smashing it repeatedly against the table next to his chair.
Medvedev was heavily fined for his behaviour at the 2025 US Open
Medvedev will lose all the prize money and ranking points he earned from his run to the semi-finals in Beijing. He remains in the eighth and final qualifying spot for November's ATP Finals, but the loss of 200 points could yet prove crucial.
The 30-year-old has apologised for his actions and said he hopes to say sorry to the spectator in person.
In New York a month ago, Medvedev reflected on the role of genetics when explaining how his eldest daughter has "my personality on the court".
"She plays a bit. She enjoys it. Maybe it's a bit of a genetic somewhere there," Medvedev added.
"I took her to practice once. She's happy, so she throws the racquet through the whole court.
"The coach looks at me and says: 'I don't know where she got this from...'
"All the people that talk about that I should control myself more - she's three years old. It's not like we taught her to do the things she's doing on the court."