Novak Djokovic was upset by Mariano Navone in a five-set marathon at the US Open on Sunday, losing 7-6 (5), 5-7, 4-6, 6-2, 6-1. The 39-year-old pushed through physical and internal ailments, making 70 unforced errors in a 4-hour-36-minute match that became the longest opening round at a Grand Slam in his career. Djokovic, the No. 4 seed and 24-time major champion, vomited during the match, appeared to be cramping, and required a medical timeout for lower back treatment.

He grimaced after several shots and could not maintain early leads, blowing 3-0 and 4-1 advantages before losing the first set—the first time this happened to him in a US Open first round since 2006. "I didn't enjoy myself... it was an awful feeling on the court," Djokovic said outside the locker room. Navone, a 25-year-old Argentine who won his first ATP title earlier this year, idolized Djokovic growing up and called it a "dream come true" after defeating him. With this loss, Djokovic will fall out of the ATP Top 10 for the first time since July 2018, raising questions about his Grand Slam future.