Nick Kyrgios made headlines for the wrong reasons again in a volatile defeat by Karen Khachanov at the Western and Southern Open in Cincinnati on Wednesday night.
The combustible Australian swore several times at umpire Fergus Murphy, refused to shake his hand at the end and also went off court to smash two rackets.
Here PA looks at some of the controversies during the 24-year-old's career.
Wawrinka sledge, March 2015
So disappointing to see a fellow athlete and colleague be so disrespectful in a way I could never even imagine.
— Stanislas Wawrinka (@stanwawrinka) August 13, 2015
Fans' favourite Stan Wawrinka was in Kyrgios' firing line at the 2015 Rogers Cup with a crude remark about his then girlfriend, fellow player Donna Vekic.
The ATP fined Kyrgios 10,000 US dollars as well as handing down a 28-day tour suspended sentence.
Wawrinka tweeted: "So disappointing to see a fellow athlete and colleague be so disrespectful in a way I could never even imagine."
Wimbledon meltdown, June 2015
After a number of controversial calls went against him, Kyrgios went into meltdown mode during his fourth-round match against Richard Gasquet at Wimbledon.
He got a code violation for swearing, argued with the umpire over whether he was taking too long to change his socks and hurled his racket into the air.
As a chorus of boos rang around the court, Kyrgios told his entourage in the coaching box to leave – bowing out of the tournament in four sets.
Shanghai strop, October 2016
Kyrgios was banned from tennis for eight weeks after appearing to give up during a straight-sets defeat to qualifier Mischa Zverev at the Shanghai Masters.
On several occasions, Kyrgios patted down tame serves or wandered off court while the rally was still going on.
He later defended his behaviour by saying he did not owe the spectators anything and that fans could "just leave" if they did not like his attitude.
The ATP fined the Australian 16,500 US dollars for failing to give a full effort, unsportsmanlike conduct and verbal abuse of a spectator.
Kyrgios was then fined an additional 25,000 US dollars and suspended for the rest of the season, a penalty that was reduced on the condition he sought psychological help.
More Shanghai drama, October 2017
🎾@NickKyrgios caused controversy at Shanghai Masters as he retired after first set against Steve Johnson in apparent protest at officiating pic.twitter.com/Nn0dQcU2rK
— PA Sport (@pasport) October 10, 2017
The following year, Kyrgios was fined again after retiring during a first-round match against Steve Johnson without any apparent health issues.
Kyrgios had responded to receiving a point penalty from the umpire during the tie-break by saying he would retire if he lost the game.
Queen's bottle incident, June 2018
Another fine came Kyrgios' way last summer after he was caught on TV mimicking a sex act with a water bottle during a change of ends at the Fever-Tree Championships. The BBC was forced to apologise to viewers.
Underarm or underhand?, February 2019
The underarm serve. 💕 The whole point of tennis competition is to disrupt ur opponents game by applying pressure through changing the speed, spin, direction, depth or height of the ball. And that includes the serve. Kyrgios is a genius. I'm surprised more players don't do it. pic.twitter.com/lBfI8XM7MN
— judy murray (@JudyMurray) March 25, 2019
Kyrgios did not break the rules but left Rafael Nadal distinctly unimpressed after attempting an underarm serve during a clash with the Spaniard at the ATP Tour event in Acapulco.
The tactic is considered unsportsmanlike by some and Nadal accused Kyrgios of being disrespectful.
The Australian has continued to use the serve in matches, with varying degrees of success, and other players have followed his example.
Raging in Rome, May 2019
Kyrgios didn't do his hot-tempered reputation any favors during Thursday's match at the Italian Open when he tossed a chair, kicked a water bottle and stormed off the court. His opponent, Casper Ruud, won by default. https://t.co/zNPfHMkaEv
— Twitter Moments (@TwitterMoments) May 16, 2019
One of Kyrgios' most spectacular meltdowns came at the Italian Open in May during a second-round clash with Casper Ruud.
The Australian reacted furiously to being docked a game for swearing at a line judge early in the third set.
He hurled a chair across the court before packing his bag and walking off before he could be officially defaulted.
He forfeited his prize money and was fined but did not face a ban.
Queen's outbursts, June 2019
Kyrgios picked up more than £13,000 in fines in one day at Queen's Club, with several flash points across two matches.
Umpire Murphy was again in the firing line, with the line-calling the subject of Kyrgios' ire, and the Australian bizarrely mocked the Irish official's hat.
