SHANGHAI (AFP) - Australian tennis firebrand Nick Kyrgios retired and stormed off the court to boos midway through his opening match at the Shanghai Masters on Tuesday, two days after his China Open final meltdown.

The 22-year-old Australian abruptly called it quits immediately after losing the first set 5-7 on a tie-break to American Steve Johnson, having been docked a penalty point for the second match running.

On Sunday, world No. 21 Kyrgios was similarly punished and had a running row with the umpire in losing the final 2-6, 1-6 in Beijing to the top seed Rafael Nadal.

A member of Kyrgios' coaching team told AFP in Shanghai that he had injured his shoulder and the temperamental Australian did look in discomfort early on in the match against his unseeded opponent.

Kyrgios, the 13th seed, 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.

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

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

He hit a low point 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.

In Shanghai meanwhile, Albert Ramos of Spain beat countryman Pablo Carreno, the seventh seed, 7-5, 7-5 to be the first to reach the third round.