A man was attacked with a metal stool while curled up on the ground at Liang Court early on Sunday morning.
A video of the incident was shared on social media, and showed the man being assaulted by at least two others in a foodcourt on the first storey of the mall.
One man shouted a string of vulgarities as he swung the metal stool, while another was seen kicking the man on the ground.
One was also seen lifting a table, but was stopped by an onlooker before he could use it to cause further hurt.
A police spokesman said they were alerted to the case of affray at about 5am on Sunday.
Officers arrested two men, both 28.
One of them was taken conscious to Singapore General Hospital.
The spokesman added that another man, 27, is assisting with investigations.
Chinese evening daily Lianhe Wanbao reported the two men who were arrested were the ones who were seen beating up the 27-year-old who was on the floor.
A food court employee told Wanbao that the man who was getting beaten up had been alone, and had a drunken disagreement with the group consisting of three men and a woman, after which they started fighting.
Wanbao also reported that the three men from the group had left the scene quickly and were headed for Fort Canning MRT station.
The woman who was with them reportedly picked up their slippers before following them.
Staff at Liang Court said drunken fights were common there, as many patrons get drunk at Clarke Quay before getting food at the mall.
In January, it was reported that a trial extension to liquor licensing hours for certain operators at Clarke Quay was ended by the police after just four months.
This was because public order crimes, which include disorderly behaviour and voluntarily causing hurt, went up by 7 per cent during the trial period, compared with the same period in 2017.
On Feb 23, a man was left with a bleeding head after being pummelled at a Woodlands coffee shop. Five men were arrested for rioting.