This is the dramatic moment a heroic waitress plunged into a pool to rescue a drowning boy in Thailand.

CCTV footage shows the youngster playing on a sunlounger unsupervised at the No.39 restaurant in Chiang Mai province on January 25.

The boy rocked the chair until it tipped forward, plunging him face-first into the shoulder-deep water, which he was unable to stand up in.

Shocked onlookers watched, seemingly afraid of jumping into the water.

As he struggled to stay afloat and dropped below the surface, a waitress rushed over and jumped to lift the drowning child out of danger. Staff checked him for injuries before returning him to his parents.

The restaurant owner said: 'We published this video of the child falling into the pool as a reminder to all parents and customers who visit our restaurant.

'We regret the incident and promise to improve and find preventive measures to keep this from happening again.'

They restaurant owner praised the waitress for her quick-thinking reactions.

He added: 'The waitress is very humble and was concerned only with checking the child was safe. We are thankful that are staff were able to help.'