World number one Novak Djokovic has been defaulted from the US Open in sensational fashion after hitting a line judge with a ball.
Djokovic appeared to hit the ball in frustration after having his serve broken by opponent Pablo Carreno Busta to trail 6-5 in the first set.
The Serbian tennis player had shown similar frustration two games earlier, slamming a ball into the advertising hoarding after failing to convert on three set points. Fortunately, no-one was struck on that occasion, but two games later Djokovic swatted a ball towards the back of the court, inadvertently striking a line judge in the throat.
You can watch the shocking incident right here:A lengthy discussion with tournament officials followed, during which Djokovic appeared to plead his case with tournament referee Soeren Friemel, the world number one eventually conceded his position, shaking hands with his Spanish opposition before leaving the court.
Djokovic exited Flushing Meadows without taking part in a press conference.

A statement issued by the United States Tennis Association in the aftermath of the incident read:
"In accordance with the Grand Slam rulebook, following his actions of intentionally hitting a ball dangerously or recklessly within the court or hitting a ball with negligent disregard of the consequences, the tournament referee defaulted Novak Djokovic from the 2020 US Open.
"Because he was defaulted, Djokovic will lose all ranking points earned at the US Open and will be fined the prize money won at the tournament in addition to any or all fines levied with respect to the offending incident."
The world number one later took to Instagram, where he apologized for the incident and vowed to learn from his behavior.
"This whole situation has left me really sad and empty. I checked on the lines person and the tournament told me that thank God she is feeling ok. I‘m extremely sorry to have caused her such stress. So unintended. So wrong. I’m not disclosing her name to respect her privacy.
"As for the disqualification, I need to go back within and work on my disappointment and turn this all into a lesson for my growth and evolution as a player and human being. I apologize to the @usopen tournament and everyone associated for my behavior. I’m very grateful to my team and family for being my rock support, and my fans for always being there with me. Thank you and I’m so sorry."
The disqualification represents a major blow for Novak Djokovic, who is looking to close the gap on total Grand Slams to Rafael Nadal and Roger Federer. The US Open, in which both Nadal and Federer opted not to play amid the coronavirus pandemic, represented a significant chance for Djokovic to edge closer to his rivals.
Related: Rafael Nadal apologizes after accidentally hitting ball girl with shot during point:Per the BBC, Djokovic's opponent Carreno Busta said of the incident:
"I didn't see the moment, I was looking at my coach, celebrating the break and then I saw the line judge on the floor. I was in shock.
"When they were talking at the net I was focused in case I had to continue playing. This moment was so long. Finally Novak gave me the hand.
"I think it was not intentional. I don't think anyone of us do this intentionally. It's just the moment. It was bad luck.
"Of course you can't do this. The rules are the rules. The referee and the supervisor did the right thing but it isn't easy to make this decision."
Meanwhile, tennis legend Billie Jean King wrote on Twitter, "Here are my thoughts on the Novak Djokovic default. First I hope the line judge is okay. The rule is the rule. It is unfortunate for everyone involved, but in this specific situation the default was the right call."
The imperious Djokovic will doubtless be back stronger than ever at the forthcoming French Open, but this decision from US Open tournament officials serves as a timely reminder that the rules of the game should apply equally to all, no matter how successful and influential they might be.