Australian firebrand Nick Kyrgios stormed off court to loud boos midway through his opening match at the Shanghai Masters on Tuesday, two days after his China Open final meltdown.

The 22-year-old fumed that he was "sick of this place" and then abruptly called it quits immediately after losing the first set 7/5 on a tie break to the American Steve Johnson, having been docked a point for the second match running.

The ATP Tour said it had launched an investigation.

On Sunday Kyrgios was similarly hit with a point penalty and had a running row with the umpire in losing the final in Beijing to Rafael Nadal 6-2, 6-1.

A member of Kyrgios's coaching team told AFP in Shanghai as the player exited the arena that the world-ranked 21 had injured his shoulder.

The temperamental Australian did look in discomfort early on in the match against the unseeded Johnson.

Kyrgios seemed untroubled however by the injury when they entered the first-set tie break, but like in the final in Beijing, his temper soon got the better of him, after he was angered by the unsettled crowd and the umpire.

Johnson, the officials and spectators on the outside hard court looked on in stunned disbelief when Kyrgios decided enough was enough.

It is just the latest controversy for Kyrgios, whose undoubted talent has often been betrayed by his quickfire temper.

He hit a lowpoint in Shanghai a year ago when he similarly left the court to jeers, having rowed with the crowd and appeared to give up in his match against Germany's Mischa Zverev. Kyrgios was consequently suspended.

He began Tuesday's match on his best behaviour but showed a first flash of irritation towards the end of the set, blasting a ball out of the court after he disagreed with a call.

He and Johnson were both comfortable on their serves and they went into the tie break with signs Kyrgios was beginning to lose his cool.

It quickly boiled over when he was irked by spectators in the close-knit arena getting up during the tie break.

"What's happening here?" he asked, before muttering: "Exactly why I shouldn't come here."

Kyrgios, who had gone up 3-0 in the tie break, appeared to blame the umpire for failing to get the spectators in line and his afternoon spiralled fast when he received a point penalty.

"What is he doing? Is this normal?" Kyrgios asked somebody in the official area of the arena, where spectators and players are in close proximity.

"Poor officiating again," Kyrgios then complained, and added: "Sick of this place."

Johnson wrapped up the set and Kyrgios decided he had had enough, shaking the hands of his opponent and the umpire - though not looking him in the eye - and packing his bag and leaving.

Source: Khaleej Times