Since coming through his first-round match here in five sets, Jannik Sinner has prioritised efficiency. His 7-5, 7-6 (4), 6-3 win against Jan-Lennard Struff was the defending champion’s fourth consecutive victory in straight sets, keeping his powder dry and any potential problems with the heat at bay, just over five weeks since his physical meltdown at Roland Garros.“Thanks for reminding me,” he told the on-court interviewer, with a chuckle, when asked if he was at all concerned about high temperatures at Wimbledon. “We worked a lot after Paris trying to understand what went wrong.”Sinner has not revealed whether his team actually found any answers. He was undoubtedly grateful to be off the court in just over two and a half hours but it was the manner in which he got the job done that was most efficient. He did have to save a set point in the second set but he also made sure that points were short, although Struff’s style of play – big serve, big hitting – also lends itself to brevity.Almost 80 per cent of the points were finished in four shots or fewer, and in that category, Sinner won 91-72, a 56 per cent success rate. It was 17-18 in the 5-8 shot category and 6-5 in the 9+ zone. Dominating the 0-4 category is key to success, especially on grass.Struff had won three five-set matches to get to the quarter-finals for the first time at any of the grand slam tournaments and the German served brilliantly in the opening stages. To 5-5 in the first set, he had dropped just four points on serve but as so often happens against great players, the first time they get a sniff, they take their chance. Sinner broke in the 11th game and then served out the first set.The Italian broke for 2-1 in the second but suffered his only blip in the following game when he was broken back. Fluency was lacking a little, and Sinner had to come up with a big serve to save a set point at 4-5. But when the set reached the tie-break, he locked down to take it 7-4 and double his lead.Sinner had a chance to break at 2-1 and 0-30 on the Struff serve at 3-2 but had to wait until 4-3 to finally take his chance, a big forehand winner doing the business. There was never any doubt he would serve it out.“It felt like I was serving quite intelligently today,” Sinner said. “Also, how I handled important moments in that match because if you lose the second set, everything can happen again. Especially with big servers, you have less control.“I felt like today was again a small step better because it was a very different opponent I faced until now. Big server here on grass is always tough. Happy about today’s performance, and now of course I try to be as ready as I can for the semis.”The world number one’s problems with heat and cramp have been well-documented and with no shade on No 1 Court until late in the third set, there might have been fears of a repeat. But Sinner said he felt fine against Struff. “It felt okay,” he said. “It was warm, but nothing crazy.“In Australia, I feel like it’s tougher because ... with hard court it comes also from underneath. It was quite dry today, which is a big difference. When it’s humid and warm, it’s different again. But no, I felt quite comfortable today. It was warm, yes. It was similar I feel like to Paris maybe. But it was okay.”Germany's Alexander Zverev celebrates winning against Czech Republic's Jiri Lehecka. Photograph: Glyn Kirk/AFP via Getty Alexander Zverev took a roundabout route into his first Wimbledon quarter-final as he completed a 6-4 7-5 3-6 7-6 (6) win against Jiri Lehecka. The match had been postponed at 3-3 in the third set on Monday night when the 11pm curfew was hit for the first time, and Zverev won only one point in three games on the resumption. But he prevailed in a fourth-set tie-break to finally make it into the last eight.The French Open champion said: “Who would’ve thought it would’ve taken me only 12 years to get here? I’m incredibly happy and relieved to achieve that but, of course, I want to play three more matches here.” – Guardian