According to Xia Qiang, head of the construction company at the site, refrigeration pipes were embedded in the design of the gymnasium. The first ice-making took 5 days, watering at -4 degree to make ice, increasing layer by layer, making 1 to 2 millimeters of ice at a time until an ice layer of more than 4 centimeters thick was made.
Earlier, Schwartzman knocked out third seed Dominic Thiem in a thrilling marathon battle which lasted over five hours, winning 7-6 (7-1), 5-7, 6-7 (8-6), 7-6 (7-5), 6-2.
The five-hour and eight-minute triumph, which was Schwartzman's first victory over a top-five player at a Grand Slam, set up a rematch of the Rome quarterfinals against Spaniard Rafael Nadal, who withstood a challenge from 19-year-old Jannik Sinner and pulled away to win 7-6 (4), 6-4, 6-1 in the last match of the day, which finished at 1:30 am on Wednesday.
"We are in a very strange situation, after a lot of months without much tennis, especially for me, that I didn't play in America, I don't know if it's a positive thing or a negative thing," Nadal said when asked how important it was to keep the early-round matches short and sweet.
Sunday's rivals are Europa League champions Sevilla, and Koeman's big issue is in defense thanks to the red card shown to Clement Lenglet against Celta on Thursday.
On the Shanghai side, Zhou Yuyan had 11 points, and Han Xu bagged 10.
Peru will be without several key players for their opening fixtures against Paraguay and Brazil. The biggest absence will be that of their captain and record scorer Paolo Guerrero, who has been ruled out for the rest of 2020 because of a ruptured anterior cruciate ligament.
The injury was confirmed shortly after Spain coach Luis Enrique had named the defender in his squad to play Portugal, Switzerland and Ukraine in the coming days.
The 2018 champion lost to Anisimova in the quarterfinals in Paris last year, but this time the Romanian needed only 54 minutes to complete a convincing victory.
Luo Xinyu bagged 18 points for Jiangsu, who also got 14 points apiece from Xu Chenyan and Jiang Jiayin.
Esteghlal had been linked with former Werder Bremen coach Alexander Nouri but they failed to reach an agreement with the German-Iranian coach due to financial disagreements.