Defender Mohammad Reza Khanzadeh, midfielders Ashkan Dejagah and Akbar Imani scored for Tractor in the first half.
Also on Thursday, former Italian international Eder scored the winner to help Jiangsu Suning beat Shangdong Luneng 1-0.
There were also second round wins for fourth seed Stefanos Tsitsipas of Greece, fifth seed Alexander Zverev of Germany and seventh seed David Goffin of Belgium.
At Rio de Janeiro's Olympic stadium, former Chelsea forward Salomon Kalou made his debut for Botafogo but could not inspire the hosts to victory over Coritiba.
In the 65th minute, Dalian's Ke Zhao added a goal of his own and sealed the 4-0 victory.
World number one Djokovic struck 51 winners to notch up the win against Edmund, extending his unbeaten run this year to 25 matches.
The result lifted Flamengo to fifth in the 20-team standings, five points behind leaders Internacional
France's Julian Alaphilippe, who lost the yellow jersey to Yates on Wednesday after being penalized for 20 seconds for taking a bottle inside the final 20km, sprinted late to finish one second ahead of the peloton.
"I have to explain my philosophy to my players, but it is not possible without playing football. This is a key issue that needs to be taken into consideration," Skocic said.
"The competitions were postponed due to the coronavirus, and we don't know when we can hold our training camp," Skocic was quoted as saying by Persian Football website.
"His ability to see space, time his movements and read the game will really complement the qualities that we have in midfield and his arrival really strengthens the depth of talent we have in that position," Solskjaer told the club website.