World number one Djokovic struck 51 winners to notch up the win against Edmund, extending his unbeaten run this year to 25 matches.
In the 65th minute, Dalian's Ke Zhao added a goal of his own and sealed the 4-0 victory.
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.
Fourth seed Naomi Osaka of Japan booked her place in the third round with a comfortable 6-1, 6-2 win over Italy's Camila Giorgi.
The 23-year-old Dutchman has signed a five-year contract at Old Trafford, with an option to extend by a further year. The transfer fee is 39 million euros (46 million U.S. dollars), which may increase to 44 million euros if certain clauses are met.
TCL, founded in 1981, is one of the leading consumer electronics companies in China and has expanded its business to over 160 countries and regions worldwide.
Nationwide demonstrations against what activists have described as police brutality and systemic racial inequality have broken out over the past few months, particularly after police killed George Floyd and shot Jacob Blake. Enditem
The announcement was made Thursday at the IFA, Internationale Funkausstellung, the world's leading trade show for consumer electronics and home appliances, in Berlin.
"It was a fantastic evening. The conditions, crowd, competition - it was all fabulous. Sam is a fabulous competitor, and I feel we bring the best out of each other," Duplantis added.
The competition in Lausanne's Place de l'Europe played host to a fascinating duel between Duplantis and two-time world champion Sam Kendricks from the United States, whose best jump was 6.02 meters.
THE HAGUE, Sept. 2 (Xinhua) -- Manchester United have signed midfielder Donny van der Beek from Ajax, both clubs announced on Wednesday.