A drunken man grabbed a woman's hair and groped her breast as she tried to remove him from Ely Cathedral, a court has heard.
Dariusz Jagielo, 54, of Ely Road, Queen Adelaide, admitted sexual assault but claimed he had been "too drunk" to remember what happened.
He told Huntingdon Magistrates' Court he regretted the incident and "had never done anything like that before".
The father-of-two was sentenced to 100 hours of unpaid work.
Kate Hatton, prosecuting, told the court that a drunken Jagielo had turned up at the cathedral at about 16:15 BST on 15 October during a private event, and had been asked to leave by a member of staff.
"It was at this point the defendant put both arms around her, kissed her cheek, grabbed her hair and groped her left breast," she said.
Speaking through a Polish interpreter, Jagielo told district judge Ken Sheraton that he had been at a birthday party and had drunk "half a litre of vodka".
"I don't remember the details of that day because I was drunk," he said.
The court heard he often dropped into the 12th Century cathedral, known as the Ship of the Fens, as he is "quite a religious man".
Jagielo had "struggled with victim empathy" after the incident, the judge heard, but "regretted it and is ashamed".
A report by the probation service added that Jagielo was deemed at low risk of re-offending, but a "medium risk" when intoxicated.
The judge ordered he be made the subject of a community order for 12 months.
Jagielo has to undergo 25 days of rehabilitation activity and 100 hours of unpaid work. He was also ordered to pay £485 costs.