Novak Djokovic has been disqualified from the US Open after hitting a line judge with a ball.
The world number one was mid-match against Pablo Carreño Busta in the fourth round of the tournament, when disaster struck.
The top-seeded player, chasing his 18th Grand Slam title, Djokovic had just lost a game to fall behind 6-5 in the first set.
He hit a ball behind him as the two players moved to the sideline for a change of sides.
The ball struck a female line judge at the back of the court, apparently in her neck, who then dropped to her knees.
After discussions with the match officials, Djokovic was disqualified, and he went to shake hands with Carreno Busta before leaving the court.
Hours later, Djokovic took to social media to apologise.
View this post on Instagram
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. Cela ova situacija me čini zaista tužnim i praznim. Proverio sam kako se oseća linijski sudija, i prema informacijama koje sam dobio, oseća se dobro, hvala Bogu. Njeno ime ne mogu da otkrijem zbog očuvanja njene privatnosti. Jako mi je žao što sam joj naneo takav stres. Nije bilo namerno. Bilo je pogrešno. Želim da ovo neprijatno iskustvo, diskvalifikaciju sa turnira, pretvorim u važnu životnu lekciju, kako bih nastavio da rastem i razvijam se kao čovek, ali i teniser. Izvinjavam se organizatorima US Opena. Veoma sam zahvalan svom timu i porodici što mi pružaju snažnu podršku, kao i mojim navijačima jer su uvek uz mene. Hvala vam i žao mi je. Bio je ovo težak dan za sve.