A day earlier, Do Xuan Hoai, a resident of the ward, spotted the animal crawling into his home.
Initially mistaking it for a snake, Hoai alerted his family. After realising it was a rare species, they captured the animal and contacted authorities.
The monitor lizard was later transferred to Vu Quang National Park, where it will be cared for before being released back into the wild.
Forest rangers identified the animal as an Asian water monitor (Varanus salvator), a protected rare and endangered forest species classified in Group IIB under Vietnamese law.
The species is also listed as vulnerable in Vietnam's Red Data Book.