Grigor Dimitrov was forced to retire from his Wimbledon clash with Jannik Sinner due to injury – despite leading the top seed by two sets.The Bulgarian stormed into a shock 6-3 7-5 lead against the world no. 1 on Centre Court, with the pair a 2-2 in the third set.Dimitrov needed medical attention for an apparent muscular injuryGettyDimitrov appeared to injure one of his pectoral muscles and needed attention from medical staff at Wimbledon.However, he was unable to continue and walked back onto the court shaking his head towards Sinner to signal his retirement.The pair walked off together and met with applause from the crowd, although Dimitrov could be seen wiping tears from his eyes.It’s the latest Grand Slam heartache for Dimitrov, who has now been forced to retire from his last five appearances in major tournaments.He had to retire at the same stage in last year’s Wimbledon against Daniil Medvedev.Sinner now faces Ben Shelton in the men’s singles quarter-finals.But the Italian only had Dimitrov in his thoughts in his post-match interview as his dream of a first Wimbledon title remains a possibility.He said: “I don’t know what to say. He is an incredible player and we all saw this today.“He has been so unlucky in the past couple of years. He is an incredible player who is a good friend of mine.“We understand each other very well off the court.Despite leading, he was unable to play on and retiredGettyDimitrov was emotional when walking off Centre CourtAFP“Seeing him in this position – if there was a chance for him to be in the next round he would deserve it. I hope he has a speedy recovery.”“I don’t take this as a win at all, this is just an unfortunate moment for us to witness,” Sinner added.“He has struggled in Grand Slams with injuries a lot so seeing him again with this injury is very tough. “We all saw by his reaction how much he cares about the sport and he is one of the hardest working players on tour.“Thank you for coming, but this is not the end we wanted to see and it’s very sad. “We all wish him only the best – let’s give an applause for him and his team.”Sinner sat with Dimitrov in a classy gestureAFPSinner has played at Wimbledon just weeks after his defeat to Carlos Alcaraz in a thrilling French Open final.The Australian Open champion has only gone as far as the semi-finals in SW19.