Valladolid and Celta drew 1-1 with Sergi Guardiola's 66th minute penalty cancelling out Iago Aspas' 44th minute strike for Celta.
All eyes were on Messi after a summer in which he had asked to leave the club and only two days after he had criticized the departure of Luis Suarez, but Fati was the star of the show.
In the 14th minute, Chongqing striker Feng Jin was knocked down by Shanghai defender Zhang Wei when he tried to make a breakthrough from the left side. Feng was rewarded with a penalty at first, but the referee decided to give Zhang a red card instead after checking the VAR.
The side coached by Diego Martinez had kicked off their campaign with league wins at home to Athletic Club and Alaves, while also getting through two Europa League qualifying rounds, with a 4-0 victory away to Albanian outfit, Teuta and a 2-0 win at home to Locomotive Tbilisi a week ago.
The match had been suspended by a Rio de Janeiro labor court on Saturday but the decision was overturned by a senior judge just 10 minutes before kickoff. The game eventually started more than 20 minutes late.
A brand-new championship format amid strict epidemic prevention measures brought about unprecedented challenges -- each team been asked to play a game every four days, and even more regularly after the CFA Cup kicked off, which forced many clubs to deal with squads plagued with niggling injuries.
Icardi found the target in each half thanks to two assists from French international Kylian Mbappe.
"My goal was to reach the podium, but I didn't expect to win the title," said Song.
The newly-renovated Nyayo National Stadium will host the Kip Keino Classic - the first-ever World Athletics Continental Tour event to be held on the African continent - on October 3.
"If we don't have advantage on strength, we should be much more confident than our opponents, and showing a stronger will to win," he added.
Flamengo entered the match with only three regular starters, having reported 16 positive coronavirus cases in their first-team squad last week. Head coach Domenec Torrent was also absent from the touchline at Allianz Parque because of the virus.