Gary Stewart Seal was arrested after the victim revealed to a relative in November 2011 what had taken place years earlier.
He protested his innocence when interviewed, and was initially accused of a total of nine charges, which he denied at Durham Crown Court last November.
Following further adjournments the case, reduced to an eight count indictment, went ahead as a trial last month.
Seal, of Rydal Road, Ferryhill, County Durham, denied three counts of indecent assault, one of causing, or inciting a child to engage in sexual activity and four of sexual activity with a child.
A jury found him ‘guilty’ of the three counts of indecent assault, but cleared him of the other five charges.
Sentence was adjourned until Friday, (May 17) when 30-year-old Seal was jailed for a total of five years.
Judge Christopher Prince told him: “The victim gave a very clear statement as to what you had done, but, you called her a liar.
“The jury didn’t believe you and convicted you of three counts. They found her to be truthful.
“The impact on the victim has been most averse and grave. "