[3][4] Đương was initially rejected because of his weight – he weighed only 32 kg at the time – but was allowed to join after two months of strength training.

[4] In October 2019, Đương knocked out the previously undefeated Jenel Lausa as the main undercard of the Victory 8: Legends of Hoan Kiem event in Hanoi.

[5][6] Đương won a silver medal in the bantamweight event at the 2019 Southeast Asian Games,[3] defeating Nanthavong Simphavong of Laos and Naing Latt of Myanmar before losing to Thai legend Chatchai-decha Butdee in the final.

[4] Although Đương lost his semifinal matchup against Mohammad Al-Wadi by split decision, his two previous victories secured his spot at the 2020 Summer Olympics,[4] making him the first-ever Vietnamese boxer to earn direct qualification to the competition (as opposed to a wild-card berth).

[8] He came in second place in a vote for Vietnam's "most valuable athlete" of 2020, ranked only behind footballer Nguyễn Văn Quyết.