Flamengo went ahead in the sixth minute when Pedro slotted a cool finish past Argentinian goalkeeper Javier Burrai after a surging run and defence-splitting pass from Gerson.
In Tuesday's match, Guoan was up by three goals before the interval, with goals from Yu Yang, Jonathan Viera and Fernando Lucas Martins.
Newly promoted Huesca then visit Valencia, who should have winger Denis Cheryshev and keeper Jasper Cillessen both available after last weekend's defeat in Vigo.
The Rubronegro reported 11 positive cases in their traveling squad after losing to Independiente 5-0 in Quito last Thursday. They beat Barcelona 2-1 in Guayaquil on Tuesday despite being forced to field a team mostly comprising reserves.
The striker said that joining Atletico Madrid was an "attractive challenge" and that he had spoken to Antoine Griezmann and Uruguay international Diego Godin about the club.
Leo Messi will also be in the spotlight after a summer in which he asked to leave the Camp Nou, while the pressure will also be ramped up on Antoine Griezmann and Philippe Coutinho, who has returned following his loan to Bayern Munich.
Although Shenzhen FC's Gao Lin managed to pull one back in the 63rd minute by seizing the spot-kick, the Shandong based club still successfully took three points, ending their four-round winless run and allowing them to temporarily upgrade to second place.
The Guinness Book of World Records has also recognized him as the first person to climb Mt. Qomolangma in winter without bottled oxygen in December 1987.
DALIAN, China, Sept. 21 (Xinhua) -- Shanghai Shenhua and Jiangsu Suning played out a 0-0 stalemate in the 12th round of the Chinese Super League (CSL) here on Monday.
The only down side for the capital-based team was that Renato Augusto limped off with injury as the Brazilian was suspected of suffering a muscular problem.
Ibrahimovic was close to finding the net in the 11th minute as his attempt went just inches past the far post after a meandering run in the box.