Grigor Dimitrov was in full control on Monday with a chance for one of the biggest upsets at Wimbledon. But an apparent pectoral injury ended his day early, and he was forced to retire while holding a two-set lead over No. 1 seed Jannik Sinner. Sinner advances to the quarterfinals after appearing to be on the verge of falling victim to a stunning Round of 16 upset. Dimitrov held a 6-3, 7-5, 2-2 lead at the time of his injury. Dimitrov, seeded 19th, retires from a Grand Slam match for a fifth straight time. He'd previously retired from Wimbledon and the US Open in 2024 and the Australian Open and French Open this year. Dimitrov sustained the injury while serving. He immediately fell to the ground in pain and clutched his right pec with his left hand. As trainers rushed to the court to tend to him, Dimitrov laughed, apparently aware of the gravity of his injury. Grigor Dimitrov was forced to retire from his match against top-seeded Jannik Sinner after appearing to injure his right pectoral.Dimitrov had won the first two sets of the match.pic.twitter.com/f5mB6Lp1eL — ESPN (@espn)July 7, 2025 Dimitrov then walked to the bench to continue to receive medical treatment before leaving the court for a medical timeout. Moments later, he returned to the court to shake Sinner's hand, having concluded that he could not continue to play. A sight we never want to see.Grigor Dimitrov is forced to retire while leading two sets to love. Everyone at#Wimbledonis wishing you a speedy recovery, Grigor 💚💜pic.twitter.com/qBwiMbq3e2 — Wimbledon (@Wimbledon)July 7, 2025 Sinner put his arm around Dimitrov's back as they walked to shake hands with the chair umpire. An appreciative Centre Court crowd gave Dimitrov a rousing ovation as he packed up his bag. The win denied Dimitrov his deepest run at Wimbledon since he advanced to the semifinals in 2014. Sinner advances to stay alive for a fourth Grand Slam victory since the 2024 Australian Open. Sinner won the Australian Open in 2024 and 2025 and secured the US Open title last fall. Sinner faced his first challenge at Wimbledon against Dimitrov following a sensational start through the first three rounds. Fresh off a run to the French Open final, Sinner cruised through the first three rounds via runaway wins by scores of (6-4, 6-3, 6-0), (6-1, 6-1, 6-3) and (6-3, 6-1, 6-1). But Dimitrov put Sinner to the test immediately by breaking his first serve of the match. Dimitrov didn't lose a service game en route to a 6-3 first-set win. Dimitrov then took immediate control of the second set by breaking Sinner's first serve again. Sinner rallied for his first break of the match to temporarily fend off a 2-0 deficit and tie the set at 5-5. But Dimitrov broke Sinner's ensuing serve, then held serve to secure the 7-5 victory and the 2-0 set lead in the match. Spelling further trouble for Sinner was a medical break during the second set. Sinner fell awkwardly on his right arm and received treatment on his elbow during the break before returning to play. Sinner was able to keep playing and broke Dimitrov's serve after the medical timeout. He told reporters after the match thathe would have an MRI on his elbow on Tuesdayto determine the nature of any injury. Sinner is scheduled to play in the quarterfinals on Wednesday. Sinner and Dimitrov each held serve in the third set en route to a 2-2 tie before Dimitrov suffered his tournament-ending injury. His retirement marked the latest injury setback for Dimitrov in a career filled with them. Dimitrov most recently retired from the first round of the French Open with a thigh injury while holding a 6-2, 6-3, 2-6 lead over American Ethan Quinn. Heretired from Wimbledon in the fourth round in 2024with an abductor tear. He trailed Daniil Medvedev, 5-3, in the first set at the time of that injury. In between, Dimitrov was forced to retire from the 2024 US Open and 2025 Australian Open. After the conclusion of the match, Sinner addressed the Centre Court crowd and Dimitrov's poor injury fortune. "I don't take this as a win at all."Jannik Sinner was full of respect for his friend Grigor Dimitrov after he was forced to retire.#Wimbledonpic.twitter.com/bQTsxUM8Mu — Wimbledon (@Wimbledon)July 7, 2025 "I don't know what to say," Sinner said. "He is an incredible player, I think we all saw this today. He's been so unlucky in the past couple of years. "An incredible player, good friend of mine also. ... Seeing him in this position, it's — honestly. If there would be a chance that he could play in the next round, he would deserve — but now, mostly, I hope he has a speedy recovery. "Very, very unlucky from his side. I don't take this as a win at all. This is just a very unfortunate moment to witness for all of us." Sinner advances to face No. 10 seed Ben Shelton in the quarterfinals in search of his first Wimbledon championship.Shelton secured a 3-6, 6-1, 7-6 (1), 7-5 winover unseeded Lorenzo Sonego earlier Monday. For Dimitrov, the retirement marks another in a Grand Slam career filled with them as he continues to seek the first Grand Slam final of his career.