Ryan English, from Castleford, went on to carry out further rape and sexual offences against the child on around 20 occasions.
Leeds Crown Court heard English, now 22, first attacked the boy when he was around 15 years old when he was working as a DJ at the West Yorkshire club.
ALSO IN COURT: NHS boss who headbutted Leeds United love rival Tony Dorigo suspended from workEnglish also targeted another victim in 2017, in the toilets of a different working men's club where he was the DJ at a fifth birthday party.
Leeds Crown Court heard on that occasion English exposed himself and performed an indecent act in front of the child.
English was arrested after the incident was reported to bar staff and police were contacted.
Louise Reevell, prosecuting, said English downloaded sickening videos on his mobile phone of children being raped after he was released on bail.
Investigations revealed he had also been in contact with someone via WhatsApp requesting indecent images of children to be sent to him.
English, of Langdale Close, Castleford, denied the offences at trial.
READ: West Yorkshire man jailed for looking at child porn says his life has been ruinedHe was convicted of three offences of rape, causing a child to engage in sexual activity, engaging in sexual activity in the presence of a child and three offences of making indecent images of a child.
A victim impact statement was read to the court on behalf of the mother of English's first victim. She described how her son had suffered nightmares and was severely traumatised by the abuse.
She said: "He is an anxious, self-conscious and angry boy."
Recorder Abdul Iqbal, QC, described the offences as "shameless and cruel".
He said: "They were crimes committed over a number of years against a young vulnerable boy.
"All of this was done to satisfy your sexual cravings in relation to young boys.
ALSO IN COURT: New trial date for Sheffield men accused of terror plot involving driverless car "You took away any semblance of a normal, happy childhood from that victim."
Detective Inspector Vanessa Rolfe, of West Yorkshire Police, said: “Ryan English clearly presents a significant danger to children and we are pleased to see him convicted and jailed at court today. “The fact that he chose to put his victims and their families through the ordeal of a trial only compounds the harm he has inflicted.
“I hope they may take some closure from seeing a dangerous man jailed for what he has done to them.”