Though it was clear that Djokovic had not intended to hit the line judge, organizers nevertheless said the Serbian was disqualified in accordance with the rules.
Cedric Bakambu continued his goal-scoring form and broke the deadlock in the 23rd minute, as he sent Zhang Yuning's pinpoint through ball into the bottom corner.
Elsewhere, Canadian rising star Denis Shapovalov stunned seventh seed David Goffin of Belgium 6-7 (0), 6-3, 6-4, 6-3 to make last eight, while Croatia's Borna Coric also advanced.
"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.
In Group B2's other match, Scotland won 2-1 against the Czech Republic, who had had to call up an entirely new squad for the match owing to COVID-19 quarantine regulations.
But before the postponed Tokyo Games begins, Wang needs to test himself in his first competition of the COVID-19-disrupted season at the National Championships starting on September 26.
It's the second straight victory for Portugal, as they defeated Croatia 4-1 at home last Saturday. They will visit France in October in their third match in Group 3.
Damjan Bohar scored the only goal for Slovenia in the 28th minute.
Teda had a poor performance in the current season, managed one draw and seven defeats before Sunday's game.
"I have a good impression about China. It's different from what you hear in Europe," Onuegbu said.
Liu was victorious in the 2019 Women's World Cup, defeating 2017 winner Zhu in last year's final.