Following a three day trial this week, James Peter Wray, of Quadring Road, Donington, was unanimously convicted of the offences, which took place between 2015 and 2018.
Wray, who failed to attend court for the last day of his trial, will be sentenced on a later date.
A spokesperson for Lincolnshire Police said: “He was charged with two counts of assaulting a child under 13 by touching.
“The charges were brought on 10 June 2021 following a thorough investigation by officers in the Protecting Vulnerable People (PVP) unit.
"The investigation was launched following an allegation by a victim who came to us in 2020.”
Detective inspector lee Nixon from PVP, commented: “The courage of the victim to come forward and report these crimes should not be underestimated, and I want to thank them for taking that brave step.
“This case demonstrates that we will take reports seriously regardless of when the abuse occurred. I am really pleased with the verdict, and while no court outcome can ever undo the suffering at the hands of the predator involved, I hope that the victim can now feel they have received justice.”