Construction worker Chinnapa Govindarasu, 31, admitted to being part of an unlawful assembly with at least four others, whose aim was to overawe by show of criminal force along Race Course Road on the night of December 8.
The charge said one or more of them used force by flipping a police car in the Little India district, where the riot broke out after an Indian man died in a fatal accident with a bus.
A district court heard that Govindarasu was heading towards Race Course Road that Sunday evening after drinking a large amount of whisky and beer with friends.
He had intended to take the transport back from the Race Course Road area to his dormitory in Kranji industrial zone.
Police arrived in two cars to handle the riot but were later unable to return to their vehicles parked along the road due to the escalating violence in the midst of some 400 migrant workers from South Asia who had gathered in the area for their weekend off.
Fifty-eight police and defence officers were injured and 23 emergency vehicles damaged in the riot in Little India, a precinct of Indian origin shops, businesses, pubs, eateries, hotels and motels.
Twenty-five Indians were charged for rioting.