This is the heart-stopping moment a quick-thinking railway guard risked his life to save a drunk who fell on a level-crossing with a train fast approaching.

The worker Trinh Van Tai, 33, lowered the barrier and waited for the locomotive to cross as usual in Long Khanh Town in Vietnam's Dong Nai Province on July 5 evening.

However, moments later an apparently drunk local, believed to be around 50 years old, stumbled under the crossing barricade, ignoring Tai's warnings while reportedly looking for cigarettes.

Due to his alleged inebriation, he tripped and fell flat onto the tracks as the train rumbled closer.

With no time to lose, Tai was seen flinging his signal light to the ground and dragging the man away from danger. He managed to make it to safety with a second to spare.

Railway guard Trinh said: 'I saw the man and told him that a train was coming. He hesitated for a bit, but still decided to trespass, only to stumble and fall right onto the track.'

Footage shows how Trinh dragged the man to safety then waved his arms in anger and frustration. Several locals shortly appeared and pulled the drunk to his feet.

He staggered and swayed but was lead away to safety, while Trinh returned to his post to carry on watching the crossing.

Tai said he has been a railway guard for 11 years, adding the incident was his closest brush with death as he only had a moment to react.

Long Khanh authorities are now preparing to reward the courageous worker for his heroic deed.