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.
The 2020 COSAFA is tentatively scheduled for Oct. 2 to 17 in Durban, South Africa, while the AFCON qualifiers will resume in November.
In the stoppage time, Zhang Yuning shot the ball into the net for Beijing, but the goal was disallowed due to offside after checking the VAR.
In the Changzhou division, Kunshan FC edged Changchun Yatai 1-0, Nantong Zhiyun held a 1-1 draw with Sichuan Jiuniu, and Xinjiang Tianshan Leopard tied with Heilongjiang Lava Spring 0-0. Enditem
New signing Donny van de Beek gave United a chance with a goal in his debut but Zaha's excellent second strike five minutes from time condemned them to defeat.
The outbreak follows Flamengo's week-long trip to Ecuador for a Copa Libertadores double-header against Independiente del Valle and Barcelona SC.
The defending Brazilian and Copa Libertadores champions said they had only nine outfield players available for the top flight fixture at Allianz Parque in Sao Paulo.
The Celta captain opened the scoring after receiving a pass from Nolito after 15 minutes in an entertaining match which saw Celta play some impressive football.
Leandro Martinez gave the hosts hope by combining with Cristian Colman and beating goalkeeper Cesar at his near post after some sloppy Flamengo defending.
The Rubronegro have remained in Ecuador ahead of Tuesday's clash in the Pacific port city of Guayaquil.
Using 100% clean energy for the Games venues, and natural carbon dioxide as refrigerant to lower carbon emissions to nearly zero in the ice-making process are some of the steps taken to make the Games green.