The raw power of Aryna Sabalenka eventually overwhelmed Katie Boulter’s guile and resilience but only after more than two hours of ebb and flow as what had looked like a mismatch on paper proved to be anything but on the grass of Wimbledon. There were 215 rungs of the ratings ladder between Sabalenka, the world No 4, and her British opponent at the start of the week, yet it was only in the last few points, as the No 2 seed broke Boulter’s serve to win 4-6, 6-3, 6-3, that there was any sense of the Belarusian taking full control. That game followed a hold of serve by the seed that could easily have been yet another turning point, but ultimately proved to be the moment when Sabalenka’s strength won out. The slams have never been kind to Sabalenka, who has yet to reach even the quarter-final stage of any of the sport’s main events, despite finishing in the top 15 of the rankings for the past three years and picking up several lesser titles along the way. It would perhaps be unfair to label her a flat-track bully but there were several moments in Wednesday’s match when Sabalenka’s belief seemed to be ebbing away, as Boulter sent back one thumping groundstroke after another before finding a clever angle or a corner to win the point. If she could stay alive long enough, there was also every chance that her opponent would make an error, though in the early exchanges that was a very big if. Sabalenka’s first serve was an ace, the second unplayable. But even at this early stage, her fragility was quickly apparent as a weak second shot into the net and then two excellent winners from Boulter produced a first break point. An ugly double fault turned it into the first break, and Boulter was up and running. The seed’s increasing frustration at how frequently her booming forehands were coming back to renew acquaintance was apparent from grunts that moved up an octave at a time, becoming shrieks of despair as rallies continued. Sabalenka’s power is exceptional on both sides and she moved through the gears on serve as well, to launch a long line of bullets at 115mph or more. Faced by an opponent who stood up to her best shots, however, she was struggling to find a plan B. The seventh game was another shocker from Sabalenka which included two double faults, the second on break point. Two fairly comfortable service games later, Boulter was a set up and Sabalenka was wobbling. The pattern of patchiness continued into the second set, which turned when Boulter was broken in the sixth game. The fifth point, at 30-30, seemed to sum up the match, as Sabalenka thumped down an increasingly desperate series of forehands and eventually mistimed one into the tramlines. But it was also a moment when she seemed to pull herself together, and a good return and then a double fault from Boulter gave her an opening which she seized with some ferocious hitting. Even so, Sabalenka struggled to get over the line when serving at 5-3 and it took an error by Boulter on set point, putting a potential winner wide after an excellent return of serve, to level it up. When Boulter was broken in the third game of the final set, it seemed like a decisive moment but two minutes later the other Sabalenka was back. A double fault, two badly mistimed groundstrokes and an overhit second shot from a so-so return saw her broken to love, and an upset was back on. Boulter could not make it count with a hold, having suffered the psychological blow of thinking she had wrapped it up to 15 when a cross-court by Sabalenka was called wide. A challenge proved that it had kissed the line and Sabalenka was immediately bludgeoning the ball with fresh belief, reeling off the next four points. Even then, it never felt as though Boulter’s cause was lost, and had she converted just one of her five break points in the eighth game the outcome might have been different. But Sabalenka came up with big serves when she needed them most, her power simply too much for Boulter at the death. “She’s clearly a champion for a reason,” Boulter said afterwards. “Those are the people that play the best points at the most important points. I had quite a few break points and didn’t manage to take them. I also didn’t feel like I gave them away. She had to win them.”