LONDON, July 3 (Reuters) - Australian showman Nick Kyrgios"s said he was playing "unbelievable" tennis before being forced to quit with an abdominal injury after two sets of his third-round Wimbledon clash against Felix Auger-Aliassime on Saturday. The 26-year-old, contesting his first tournament since the Australian Open in February after a self-imposed COVID-19 exile, won the first set 6-2 but was clearly hampered as he lost the second 6-1, having had a medical timeout. He then decided he could no longer play on. It was an anti-climax for a Court One crowd who were mesmerised by Kyrgios"s play early on as he outplayed the 16th seed, breaking his serve three times. But at 5-2 ahead it all began to go wrong as a damaged abdominal muscle began to make him grimace on serve. He said the injury occurred when serving at 4-1. "As soon as I served, I felt an acute pain. I knew I was in a bit of trouble," Kyrgios, who burst into the limelight by beating Rafa Nadal in 2014, told reporters. "It"s funny because I woke up today feeling phenomenal. My hips felt good, my body felt good. I was like, wow, I"m back, I"m feeling good. The luck just didn"t go my way. "In a way he was a bit lucky because I felt today I was playing unbelievable. I came out of the blocks, I was returning lights out. I was actually finding my stride. I"ve never felt more comfortable on the grass, honestly. I was hot." Kyrgios had reminded fans of his shot-making wizardry in a rivetting five-set win over Frenchman Ugo Umbert in the first round, then again against Italian Gianluca Mager. But with so few matches in the tank since the start of 2020 -- this was his sixth tournament in that spell -- he said that his lack of preparation, having arrived four days before the start, had made it challenging on his body. "My game is obviously there. He"s 15 in the world. I"m making the guy look pretty average in the first set, and I haven"t played a tournament in six months," he said. "My body, I got to get it right. Whether that takes a week or two weeks, it is what it is. It was heartbreaking for me. I"m enjoying myself. Going from the bad boy of tennis, all this stuff, to now one of the crowd favourites." Kyrgios said he was dreading telling Venus Williams he would not be able to continue in the mixed doubles. "It"s brutal for me," he said. "I don"t want to think about telling Venus just yet," he said. He also cast doubt, once again, on playing at the Tokyo Olympics despite being included in the player list. "The Olympics, the way it"s going to go on, is not the Olympics. That"s not what it is for me," he said. "With these restrictions, that"s not how I want to remember the Olympics either if I play it just one time."