Nick Kyrgios courted controversy once again at the Shanghai Masters on Tuesday, retiring midway through his match with Steve Johnson for seemingly no reason. The Australian enjoyed a run to the China Open final last week, only to be outclassed by Rafael Nadal after appearing to be negatively affected by a line call going against him in the opening game. In the wake of that defeat, Kyrgios revealed that his charitable foundation to help disadvantaged and underprivileged children has given him a fresh focus to motivate himself. But there was little sign of the 22-year-old turning over a new leaf as he shook hands with Johnson and promptly walked off court after losing the first set on a tie-break. (Video Credit: SNTV)