Djokovic sorry for hitting line judge: 'So unintended'

World No. 1 Novak Djokovic apologized after he was disqualified from the US Open for inadvertently hitting a lineswoman with a ball on Sunday.

After Djokovic lost serve to trail 6-5 in the opening set against Pablo Carreno Busta, the visibly frustrated tournament favorite took a ball from his pocket and hit it behind him, striking a line judge in the neck.

Djokovic was eventually defaulted from the fourth-round match after a lengthy discussion with tournament officials.

"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," Djokovic, who didn't attend his post-match press conference, said on Instagram. "I'm extremely sorry to have caused her such stress. So unintended. So wrong."

He added, "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 US Open 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 was the Serbian's first loss of 2020; Djokovic had won all 26 of his singles matches heading into Sunday's action.

He was seeking his 18th Grand Slam title as he continues to chase down Roger Federer in the race for most major championships in the history of men's tennis.