The Foals responded but neither Stefan Lainer nor Lars Stindl was able to overcome Burki before the half-time whistle.
RB Leipzig will take on Mainz in front of 8,500 fans on the stands, while Eintracht Frankfurt is allowed to play with a 6,500 crowd against league newcomer Arminia Bielefeld. Borussia Dortmund is aiming for 10,000 spectators in its encounter against Moenchengladbach.
CONMEBOL says it has imposed strict sanitary protocols for the tournament, in accordance with requirements in each of the confederation's 10 member nations.
The "BVB" smoothed the way for their win with three first-half goals, while Dominic Volkmer's red card before half-time left Duisburg hopeless.
Elsewhere on Tuesday, Ecuador's LDU Quito secured a 1-0 win away to Peru's Binacional, courtesy of a first-half goal from Matias Zunino.
However, speaking to Xinhua on Wednesday, Gor chairman Ambrose Rachier, said the record 19-time domestic league winners were focused on signing new players whilst ensuring their players keep fit in small groups as COVID-19 protocols dictate.
"I used to fail in the final shot, this time I was the one who turned the tide," Liu said with a smile.
Guoan went ahead before the interval as Cedric Bakambu headed home a cross from Augusto. Substitute Alan Douglas scored in the 88th minute to extended Guoan's lead to 3-1, but Hebei's Zhang Chengdong sparked the game into suspense with a powerful shot in the second minute of stoppage.
"Hopefully now I can get some match fitness, get underway and really help the team to win trophies."
Leo Messi scored twice, and set up Philippe Coutinho, to show that he is fully committed on the pitch after a summer in which it looked as if he had a foot outside the door of the Camp Nou, while Barca produced a mobile performance in a side that contained Messi, Antoine Griezmann, Coutinho and newcomer Francisco Trincao.
The decision was widely welcomed not only by professional football clubs but other sports such as handball and basketball.