LONDON: There have been few authoritative reports on Jannik Sinner over the past few seasons. The defending champion pumped 52 unforced errors in three hours and 32 minutes, while his own Wimbledon title defense threatened to be irreversible, recovered from one set to two to win.The 24-year-old won his 94th Grand Slam match with a 4-6, 6-3, 6-7 (6), 6-2, 6-3 victory over Miomir Kecmanovic.“I was a little tough at the beginning, I didn’t play well, but I tried to get into it. It was my first official match on grass this year. I’m glad I turned it around. The third quarter was hard to swallow,” said Sinner. “It was a very different feeling. There’s a lot of nerves when you walk down the stairs to (get to) the court. Also knowing that it’s a very prestigious court. To come back here as a defense attorney means a lot to me.“The home crowd at SW19 endured the opening day. After Emma Raducanu left late on Sunday, Britain’s Jack Draper, who was injured in the former world 4, left the race, although the evening sun provided relief from the hot English summer. On Center Court, there was little comfort as Sinner spent most of the afternoon walking the rim, battling technical, technical and physical challenges.Sinner, playing his first match since his surprise second-round exit at Roland Garros last month, where he appeared to be craving heat, returned to Center Court with questions still hanging over him. Across the net stood spirit world No. 50, Kecmanovic stopped.Few things came easily. The Italian’s shot selection faded, he was shooting behind the baseline, and his forehand was erratic as he surrendered in the ninth game of the opening game. Kecmanovic, 26, seized the opportunity without hesitation. Even after Sinner took a 3-0 lead in the second set, his game continued to struggle. When the temperature rose to 24°C, he reached for the ice towel.Then, after leveling the match, Sinner fell badly in the fifth game of the third set, his knee apparently giving out under him. Center Court took a breather as the defender collapsed in pain, before quickly responding on the next point, sending the crowd into a frenzy. Even so, there was little they could do when the Serbs regained the leadership.Sinner, encouraged by his box, trainers Darren Cahill and Simone Vagnozzi, who seemed to be playing with each point when the world 1 repeatedly turned to them in the most important moments, did well to get himself out of trouble. As he came close to refereeing the match at two apiece, a red stain appeared on one corner of his shoe, which caused concern in the stands, although the referee did not notice.“I’m fine, it just looks worse than it is. I’m really surprised that they let me continue playing because all the whites turned a little red,” he said. “It’s just a nail, I didn’t want to disturb Miomir, we both had a good song. I didn’t want to take time.”On the Center Court, Naomi Osaka, who retired from her previous match, the final of the WTA 500 in Bad Homburg on Saturday, with a foot injury, arrived on the court looking white led by a kimono. Underneath the traditional styling, her matching dress was a beautiful one with floral embellishments, small pleats and pleats.The Japanese star impressed on court again, showing no sign of the injury that had plagued her 48 hours earlier, as she recorded a 6-1, 7-5 win over France’s Elsa Jacquemot.Meanwhile, French Open runner-up Maja Chwalinska was just one point away from winning the first round of Wimbledon before breaking through as she raced from behind to turn the tournament around, as she led 6-2, 5-2, on her head.The Pole, who made a surprise run to the Roland Garros final in June, looked to be on the way to SW19 as he led Thailand’s Mananchaya Sawangkaew before breaking through 2-6, 7-5, 6-2.