NEW YORK, NEW YORK – SEPTEMBER 06: Novak Djokovic of Serbia tends to a line judge who was hit with the ball during his Men’s Singles fourth round match against Pablo Carreno Busta of Spain on Day Seven of the 2020 US Open at the USTA Billie Jean King National Tennis Center on September 6, 2020 in the Queens borough of New York City. (Photo by Al Bello/Getty Images) The US Open was supposed to be a slam dunk for Novak Djokovic but instead of moving closer to Roger Federer in the Grand Slam record books, the world No. 1 was defaulted Sunday when he struck a line judge with a ball. The Serb had just been broken to trail 6-5 in the first set against Spain’s Pablo Carreno Busta when he hit a ball behind him on the court. Djokovic wouldn’t have been aiming at anyone but it hit the line judge — seemingly near the face — and she fell to the ground. The chair umpire, Aurelie Tourte, and Djokovic, went to check on her before they were joined on court by tournament referee Soeren Friemel and supervisor Andreas Egli. Djokovic then had an extended conversation with Friemel before he was officially defaulted. He left the tournament site without speaking to the media. In truth, according to the rules, default was going to be the only outcome even if the intent wasn’t there from Djokovic, although Slovenia’s Aljaz Bedene wasn’t defaulted last week at the Western & Southern Open when he hit a ball and it struck a cameraman. “Players shall not at any time physically abuse any official, opponent, spectator or other person within the precincts of the tournament site,” according to the Grand Slam rule book. Djokovic had no recourse since the Grand Slam rule book states that, “in all cases of default, the decision of the referee in consultation with the Grand Slam chief of supervisors shall be final and unappealable.” Moments earlier, he had smacked a ball in frustration when he was unable to convert three set points at 5-4. He did not receive a warning ball abuse. Then he took a tumble in the 11th game, appearing to injure his shoulder. The trainer came out to visit the 17-time Grand Slam winner in the middle of the game before Djokovic returned to the court. In the past, Djokovic has received ball abuse warnings and been asked about his on-court conduct in news conferences. Defaults in tennis, especially in Grand Slams, are extremely rare. Former Wimbledon semifinalist Tim Henman was defaulted when he struck a ball and it hit a ball girl at Wimbledon in 1995. John McEnroe was defaulted for several violations — not one, like in Djokovic’s case — in a match at the Australian Open in 1990. In a 2012 ATP tournament in London, David Nalbandian was defaulted from the final when he kicked an advertising board that then hit a line judge. Denis Shapovalov, who faces David Goffin in Sunday’s night session at the Open, was defaulted when he struck an umpire in the eye with a ball at the Davis Cup in 2017.