A man who spat on a priest as an Orange walk marched past a church was caught by his DNA, a court has heard.
Bradley Wallace, 24, admitted assaulting Canon Thomas White near St Alphonsus' Church in Glasgow in July last year.
Police tracked him down after a vestment worn by Father White was sent for forensic analysis.
Sheriff Andrew Cubie told Wallace - from South Lanarkshire - that his attack was "disgusting and cowardly".
Glasgow Sheriff Court heard that about 8,000 people had attended and watched the annual Boyne Parade in the city.
As the parade was on its return route some of the crowd splintered off and walked past St Alphonsus Church off the city's London Road.
The court was told Father White had finished his Sunday mass and was at the front entrance to say goodbye to his parishioners.
When the priest saw the parade coming towards the church he tried to get back inside but was unable to due to a bottleneck of people leaving the church.
Procurator fiscal depute Chris Farrell said: "At this time the members of the public associating themselves with the parade began to sing sectarian songs and shout words at Father White and the parishioners.
"This included terms such as 'Fenian scum', 'beast' and 'paedophile'."
A large scale disturbance then broke out nearby and diverted police officers away from the front of the church where they had been stationed.
Mr Farrell said the absence of police officers saw the group become more volatile towards the congregation.
The court heard that "a number of this group began to spit towards them" and Wallace, who was in this group, spat on Father White's back.
Police took the vestment worn by Father White at the time for forensic analysis and a DNA 'hit' matching Wallace was found.
Wallace, from Uddingston, pled guilty to assaulting Father White on 7 July last year at Glasgow Sheriff Court on Wednesday.
Sheriff Cubie told him: "I want you to be under no illusion at all, spitting is disgusting and cowardly and this was done in the context of a sectarian atmosphere which is an embarrassment to the west of Scotland.
"You should be under no illusion all options are open to the court."
Wallace had his bail continued and will be sentenced later.