He was made to lick a slipper belonging to one of his tormentors and the slipper was later rubbed against his mouth.
The 21-year-old Singaporean was also kicked and punched repeatedly.
The humiliation faced by Mr Lee Chern Hao on Nov 9 last year did not end there.
He was made to kneel and apologise to one of the seven teenagers who had cornered him.
The factory worker was then ordered to crawl down a staircase like a dog. Despite being in pain, he complied with the insulting instructions.
Yesterday, South Korean Kim Chaemin, 18, was fined $6,000 for being part of this unlawful assembly.
Kim, who was a student at the time, was not present when the evening assault, which was sparked by a "dispute settlement", started at Lot 1 mall in Choa Chu Kang.
Mr Lee was taken to K-Box, a karaoke joint on the fifth storey of Lot 1, to meet one of the teenagers and then to a nearby staircase landing where he was assaulted.
Kim joined members of the group, who were his friends, after receiving information about the location of the incident.
When he arrived, Kim slapped Mr Lee twice and kicked him in the stomach and knee.
Court documents stated that Kim had attacked Mr Lee because he was "angry that the victim had wasted his time, since Kim had to rush down from his girlfriend's place".
The prosecution argued yesterday that Kim "had crossed the custodial threshold" and his role in the incident cannot be considered minor as he had taken part in the unlawful assembly while being investigated for a previous offence of affray on July 30 last year.
Kim's lawyer, Mr Sarbrinder Singh, disagreed, arguing for a fine instead.
He said of Kim: "He was not the mastermind, he played a minor role and only subsequently joined the assembly."
Mr Lee suffered multiple bruises on his cheeks, chest, back, arm and elbow, as well as swellings on his jaw and forearm.
During mitigation, Mr Singh said Kim's student pass had been cancelled.
The trauma of spending nine days in remand had also been punishment for his client.
Mr Singh added that Kim had rendered assistance to the victim after the assault.
Kim, who has been living in Singapore for eight years, told District Judge Mathew Joseph: "I would like to apologise to those (whom) I have given trouble to. If given a chance, I would change myself."
Mr Joseph fined Kim $1,000 for his other offence of affray, which took place at Teban Gardens Road when he fought with a 21-year-old man.
The others who took part in the unlawful assembly have been dealt with and given probation.
This article was first published on Nov 22, 2014. Get The New Paper for more stories.