This is the sickening moment a youth team footballer knocks out his opponent on the pitch.

With the ball long gone, the shocking footage shows the Morecambe U18s striker appearing to launch his right fist into the temple of unaware Oldham Under 18s starlet Jack Tuohy.

The sucker punch – creating a disturbing audible moment of impact - sends Tuohy, who had his back turned, crashing to the turf and seemingly unconscious.

VIDEO: Scroll down to watch the sickening punch that knocks out Oldham youngster

Jack Touhy is struck from behind in the head, apparently with no provocation, by an opponenent

The Oldham youth player is knocked from his feet as he is knocked out by the punch

Tuohy later went to hospital after beginning to feel sick while his opponent was shown the red card for his staggering act of violence.

The dramatic clip was taken during the second-half of Oldham's 7-2 victory over Morecambe at the club's Chapel Road Training Ground on Saturday.

One witness said: 'It was Morecambe's number nine who lost it. Minutes earlier he had elbowed one of the Oldham lads in the face. The ref didn't see it and Oldham took the player off because he was bleeding and he had lost it.

'Then the ball has gone and the same lad just whacks another Oldham player in the face as he has his back turned and is running away.

The striker had reportedly also elbowed an opponent just a few moments before

The Morecambe No 9 keeps running past the young Oldham star as if nothing had happened

'In years and years of watching football I have never seen anything like it.'

The witness added: 'I don't think the ref saw this one either but the Oldham players came running over and the linesman ran onto the pitch.

'He then sent the Morecambe lad off.'

Oldham declined to comment on the incident but Sportsmail understands Tuohy was sent home after being checked over at hospital later on Saturday.

After the game he tweeted: 'Good 7-2 win good to get a goal and head is killing me now wow.'