It is understood that they had a dispute over a restaurant bill, Shin Min Daily News reported.
The altercation between the owner and employees of the restaurant, and a group of diners occurred after the diners refused to pay their bill.
The four diners claimed that the bill of $120 was too expensive.
The four had drunk 24 bottles of beer and ordered some dishes, a restaurant employee told Shin Min.
Police said that they received a call about the incident at Block 261 Yishun Street 22 at about 9.54pm.
Four people were taken to Khoo Teck Puat Hospital, and seven people arrested in relation to the case, police said.
Hospital staff were asked to be on standby for one of the casualties, the Singapore Civil Defence Force said.
Police investigations are still going on.
Mr Tan, 25, told Shin Min that he witnessed the violent fight.
“They threw chairs, smashed beer bottles and ran to the bicycle stand at the next block to fight,” he said.
At one point in the 10-minute brawl, they stopped and three of the men began walking to the carpark, but the other group gave chase, Mr Tan said.
They shouted as they chased each other, then fought under another block of flats.
The fight only stopped when many of them were bleeding, and the police and ambulances arrived shortly.
Three of the men received treatment outside the restaurant, Shin Min said.