Nick Kyrgios loses it at chair umpire during Miami Open loss to Jannik Sinner

Nick Kyrgios has had another monumental meltdown, losing his cool, losing his way and eventually losing all respect in an ugly defeat at the Miami Open.

Against Jannik Sinner, the Australian let himself down once more with a display of petulance and contemptuous treatment of umpire Carlos Bernardes.

Kyrgios was just one more outburst from being defaulted in the match but after being penalised a game's loss at the start of the second set, losing 7-6 (7-3) 6-3 in his last-16 match.

It was the second tournament in a row in the US where the volcanic Australian has exited amid sorry scenes.

It followed the $25,000 the serial offender was fined for nearly hitting a ball boy after smashing his racquet and yelling an obscenity during his Indian Wells loss to Rafael Nadal.

His latest exit exhibited all the hallmarks of Kyrgios once again feeling the world was against him, as he moaned from the start about the state of the court, about the «worst» US crowd and about Brazilian umpire Bernardes being unable to control proceedings.

The sadness, as so often, was that his behaviour spoiled some thrilling tennis between the pair with the 20-year-old Sinner working wonders to blank out the noise surrounding Kyrgios and to play a consummate match.

Perhaps the Italian's performance as the better player on the day only irritated Kyrgios further as he launched a familiar war with the crowd, muttering at one changeover: «The crowd's the worst, everyone's just the worst.»

It was, to be fair to Kyrgios, a bit of a circus, with one spectator crashing the court to try to get a selfie, but he only succeeded in adding fuel to the fire.

Being outplayed in the opening set tiebreak, Kyrgios turned his attack on Bernardes, telling him: «You have absolutely no