Judge Roger Thomas QC sentenced Mark Chambers, 49, to two-and-a-half years in prison and placed him on the sex offenders' register indefinitely during a hearing held at Sheffield Crown Court on Friday.
Chambers, of Gordon Road, Edlington pleaded guilty to charges of sexually assaulting a girl under the age of 13, and causing a child under the age of 13 to engage in sexual activity at a hearing held at Doncaster Magistrates' Court last month.
The court heard how both offences were committed in June this year against a girl under the age of 13, who cannot be named for legal reasons.
Prosecutor, Ian Goldsack, said Chambers sexually assaulted the girl, and later went on to ask her if he could kiss her and touch her sexually.
The girl said 'no' to everything he asked, and he told her not to tell anyone what had happened because 'he would go to prison'.
Chambers' attempts to conceal his offending were not successful because the girl told her family what he had done to her, and he was arrested shortly afterwards.
"The defendant was arrested. He made various comments following his arrest, suggesting his guilt," added Mr Goldsack.
He added: "He maintained he was very drunk, having had a lot of vodka to drink."
Richard Adams, defending, said: "This defendant is very deeply ashamed of what he has done."
He added: "After proceedings prior to these ones he has tried to take his own life. He has accepted he needs to engage with the activities that have been offered to him in prison."
Sending Chambers to prison, Judge Thomas told him how his victim must have felt like the offences he committed against her 'went on for an eternity'.
He added: "The police noted that there was a considerable amount of remorse being expressed in the way you fully admitted what you had done.
* South Yorkshire Police have been asked to provide a custody image of Chambers