The lion had been locked in a staring contest with the youngster but when the two-year-old looked away the big cat pounced.
This is the astonishing moment a lion pounced at a young child – but was stopped only by the glass separating him from the outside world.
The big cat slammed head first into the enclosure's screen after lunging at the two-year-old seconds after the youngster turned his back.
The lion, which can run at speeds of up to 50mph, had been locked in a staring contest with the visitor at a zoo in Japan.
He prowled down from a rock and into prime position directly across from the child.
When the youngster, wearing a bright yellow jacket, looked away the big cat took the opportunity to spring forward before slamming full-force into the enclosure wall.
The child can then be seen turning around and jumping back in fear at the sudden sight of the enormous lion, which weighs 181kg.
Keepers have insisted the jump was not an act of aggression – and say the lion regularly pounces at children because he wants to play with him.
It comes just days after Harambe the gorilla was shot dead by keepers after a child got into his enclosure.
Isiah Dickerson, who was with his mother Michelle Gregg, 36, entered the enclosure after saying: "Mummy, I want to swim with the gorilla."
Both parents were widely condemned after the incident for 'taking their eye' off him, foreign media reports.
Watch the video below….