No-one likes losing in any kind of sport, especially when it's at a major championship.But you should lose with grace and dignity, even if you feel like you should have won.Try telling that to Jack Sock though.The American who is ranked 15th in the world was 2-0 up in his first round Wimbledon match with Italian rookie Matteo Berrettini, and a passage to the second round seemed inevitable.But Sock seemed to struggle with an injury and lost the remaining three sets to Berretteni, who stands at number 81 in the men's rankings.Despite being relatively inexperienced when it comes to the big stage, Berrettini did get to round three of the French Open just a few weeks ago, where he was defeated by Dominic Thiem, who went on to be stopped by the king of clay Rafael Nadal in the final.Sock meanwhile has had a tough 2018, going out at the first hurdle in both the Australian and French Open, and this most recent loss makes it four Grand Slam's in a row where the 25-year-old has been eliminated in the first round.Something clearly agitated the American during the match though, as cameras caught him insulting Berrettini's coach at the net following the Italian's victory.

"Your coach is a piece of **** by the way," Sock told his opponent.

Classy.

It seems as though there could be more to it however, as Sock told the umpire that Berrettini's coach called him 'b*******' at least three times, according to this tweet.

Whilst it's obvious something must have been said prior to annoy Sock so much, there's no reason to say what he said, especially when there are cameras and microphones all around the court to pick up every little word.

He even left the complex without completing his media requirements, according to New York Times writer Ben Rothenburg, which won't have gained him too many more fans within the journalism world.

Tennis enthusiasts in their droves were far from pleased with what they saw from Sock following his outburst.