Defender Mohammad Reza Khanzadeh, midfielders Ashkan Dejagah and Akbar Imani scored for Tractor in the first half.
Arrascaeta restored his team's two-goal advantage with a diving header in heavy rain but Jose Pimentel responded with his side's second goal just before halftime.
Djokovic will face Jan-Lennard Struff for a spot in the round of 16. The German needed one hour and 40 minutes to move past American Michael Mmoh 6-2, 6-2, 7-5.
Marouane Fellaini (R) of Shandong Luneng vies with Wu Xi of Jiangsu Suning during the 9th round match between Shandong Luneng and Jiangsu Suning at the postponed 2020 season Chinese Football Association Super League (CSL) Dalian Division in Dalian, northeast China's Liaoning Province, Sept. 3, 2020. (Xinhua/Pan Yulong)
The league association is happy about setting up concepts, allowing a certain number of fans to return to stadiums using a day-to-day approach considering infection numbers.
Moreno remained in the thick of things and kept Germany's defense busy as the striker hit an effort on target from a promising position in the dying seconds of the first half.
As the match progressed, Joachim Low's men retreated with their narrow lead and kept all their men behind the ball.
He doubled Flamengo's lead with a low shot that rebounded in off the post before Rodriguinho pegged a goal back for the hosts.
"Kyle played a fantastic first set," added Djokovic. "He didn't do much wrong, he served very well and was aggressive from the back of the court. Usually his forehand is a weapon, but his backhand, especially in the first set, was very strong, very solid."
WASHINGTON, Sept. 2 (Xinhua) -- Men's top seed Novak Djokovic of Serbia survived a first set scare to beat Britain's Kyle Edmund 6-7 (5), 6-3, 6-4, 6-2 in the second round of the US Open, while women's top seed Karolina Pliskova suffered an early exit on Wednesday.
"TCL is honored to enter into this new cooperation with FIBA for the next four years," Wei Yuki, vice president of TCL said. "Working together again with FIBA, TCL will continue to accelerate their international presence and contribute to the development and progress of global basketball." Enditem