In his quest to win a record-extending 25th grand slam title, Novak Djokovic cares only about results. How perfectly he plays holds less importance. On Sunday at Wimbledon he was pushed hard by the Russian Roman Safiullin, and at times he cut a frustrated figure on Centre Court as his game didn’t flow the way it usually does. But for a record 106th time here, he came out on top, reaching the quarter-finals for the ninth time in a row and a 17th occasion in all. The 39-year-old has now made the quarter-finals of a major tournament 66 times.Djokovic’s 7-6 (6), 6-3, 3-6, 6-3 victory against Safiullin required almost three and a half hours of effort on another warm afternoon in which he was rattled at times, mostly by the performance of the Russian, who played far more like his career-high ranking of 36 than his present mark of 132. Safiullin had two set points at 5-2 in the opening set only to be edged out in a tiebreak and was good enough to take the third set before Djokovic raised his game at the start of the fourth to avoid it going to a decider.“Another hard-fought win,” a clearly relieved Djokovic said. “Roman started very well. He was very aggressive. I didn’t maybe feel as comfortable from the back of the court. I knew it was going to be a challenge staying in the rallies with him, particularly from the end where we were playing against the wind for pretty much the whole match.“I don’t get to feel inferior from the back of the court against too many players throughout my career, if I’m totally honest. Today was one of those days where I didn’t want to stay in the rallies too long, to be honest, so I had to mix things up. It worked in some moments and in others it didn’t. In the end, I managed to find the accuracy and precision on my first serve, which really got me out of trouble in the fourth set.”Asked to sum up his first week’s efforts, “Survive to thrive, that’s how I feel,” Djokovic said. “Hopefully the thriving part is coming.” When told he is famous for his focus, he added an honest observation. “And the outbursts as well, the meltdowns. I had a few of those today as well, I apologise.”He will now face either Felix Auger Aliassime of Canada, the No 3 seed, or Alejandro Davidovich Fokina of Spain.Elsewhere, Naomi Osaka handed Aryna Sabalenka her earliest grand slam defeat for four years to firmly establish herself as a Wimbledon title contender.Naomi Osaka of Japan reacts after victory against Aryna Sabalenka during their fourth round singles match at Wimbledon. Photograph: Cameron Spencer/Getty Images In the biggest match of the women’s tournament so far, Osaka outplayed Sabalenka in a 6-2 7-6 (2) victory to send the world number one tumbling out of a major tournament before the quarter-finals for the first time since the French Open in 2022.Sabalenka has not been at her best since winning the Sunshine Double of Indian Wells and Miami in the spring and even her proud record of having won 21 consecutive grand slam tie-breaks went here on what was decisively Osaka’s day.The 28-year-old beamed after clinching one of her best wins since her last slam title in 2021, and she said: “I think it was a really fun match, I’m really grateful.“For me this court is so special, this is the first match I’ve won on this court. It means a lot. My mum’s over there and I feel like her cooking is powering me.“It’s been a long time since I’ve had so much fun on the court. Going into the match I’d lost to her three times in a row so that really sucked.”Osaka said ahead of the contest that she finds Centre Court the scariest of all the grand slam main stages but it did not appear that way as she set about demolishing the top seed.Her serve, in particular, was a fearsome weapon that Sabalenka could not get anywhere near. After looking comfortable in the first set she dominated the tie-break, with the top seed earning boos from the crowd for whacking a ball on to the roof in annoyance after netting a final backhand.Sabalenka will remain on top of the rankings after the tournament but it has been an unsettling period for her, having fallen apart against Diana Shnaider in the quarter-finals in Paris and has now seen another opportunity to win a first Wimbledon title slip through her fingers.