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The side are coached by Chan Yuen-ting, who is the first woman to lead a men's team in a continental competition.
However, her side trailed after four minutes and were reduced to nine men before the break.
Yuen-ting was the first woman to lead a men's team to a title when her side won the Hong Kong top flight in 2016.
Eastern, the first team to represent Hong Kong at the Asian Champions League, suffered a 7-0 thrashing by Chinese side Guangzhou Evergrande.