Daniil Medvedev struggled with the heat in Tokyo before battling through to the quarter-finals of the Olympics, even asking the chair umpire who would be responsible if he died. The Russian second seed defeated Italy's Fabio Fognini 6-2, 3-6, 6-2 to set up a last-eight meeting with Pablo Carreno Busta of Spain at Ariake Tennis Park, staying on course to meet Novak Djokovic for the title. Two-time Grand Slam runner-up Medvedev, who had <a href="https://www.thenationalnews.com/sport/olympics/2021/07/24/novak-djokovic-urges-later-start-times-to-combat-heat-after-winning-tokyo-olympics-opener/" target="_blank">urged organisers to delay start times</a> after his opening match, again found the temperatures testing as the extreme weather policy was implemented. "Even from the first set I didn't feel good enough with my breathing. I felt like my diaphragm was blocked, I couldn't breathe properly," said Medvedev, who took a medical timeout and received two visits from the trainer. Asked by the umpire if he was okay during the second set, the Russian replied: "I can finish the match, but I can die. If I die, are you going to be responsible?" "I think it was the most humid day we had so far, maybe the hottest," Medvedev said. "The sun was pretty hot. At the end of the second set I just had darkness in my eyes. I was bending over, and I couldn't get my breathing together. I was ready to just fall down on the court." Following a 10-minute interval between the second and third sets, Medvedev broke Fognini and won the first three games of the decider. Medvedev saved three break points at 4-2 before clinching victory after two hours and 25 minutes. Medvedev renewed calls to start matches later as temperatures peaked at 32 Celsius, with the heat index topping out at 37C. "They should start the matches later, I said it from the first round, and I continue saying it," said Medvedev. "I heard maybe from tomorrow they're going to change it, but let's see." Djokovic had joined Medvedev's calls for later start times, but if the heat and humidity is affecting him, he certainly didn't let it show on Wednesday as the world No 1 crushed Spain's Alejandro Davidovich Fokina 6-3, 6-1 to reach the quarters. Djokovic, the Australian Open, Roland Garros, and Wimbledon champion, is now three wins away from taking a giant step towards an unprecedented golden Grand Slam. Should he clinch gold in Tokyo, he will need to win the US Open to join Steffi Graf as the only other player to win all four majors and the Olympic title in the same year. The victory sets up the undisputed tie of the last-eight against Japan's greatest ever male player Kei Nishikori, who booked his place in the quarter-finals with a 7-6, 6-0 win over lya Ivashka of Belarus. Nishikori, a former world No 4 and US Open finalist, is Japan's remaining hope in the tennis singles following first round defeats for Yoshihito Nishioka, Yuichi Sugita, and Taro Daniel in the men's draw, and early losses in the women's tournament for world No 2 Naomi Osaka, Misaki Doi, and Nao Hibino. The other two men's quarter-finals will see Germany's fourth seed Alexander Zverev face Jeremy Chardy of France and Russia's Karen Khachanov take on Frenchman Ugo Humbert. <br/>