Police were called to the Temple nightclub at 540 Howard St. at about 1:20 a.m. on a report of a fight inside the club.
Officers found a 30-year-old man unconscious on the floor inside the club, police said.
The man had apparently been struck in the head with an object. He remains on life support at a hospital but is not expected to survive, police said. His name has not been released.
Another man, age 26, suffered minor injuries in the fight, police said.
The suspects, described as Asian males approximately 25 years old, fled the scene, police said.
About 20 minutes later, another fight broke out outside the club.
Police said two men, ages 25 and 34, were stabbed with broken bottles by three Asian males who then fled.
Those victims' injuries were not believed to be life-threatening.
No arrests have been made.