Officers were dispatched at about 2 a.m. to Sixth Street and Alexandria Avenue, the Los Angeles Police Department's Media Relations Section reported.
The victim was trying to break up a fight when he was stabbed, police said. Paramedics rushed him to a hospital, where he died from his injuries.
After the stabbing two of the suspects kicked the victim's companion causing non-life-threatening injuries. That victim was also taken to a hospital.
Anyone with information about the attack was asked to call LAPD West Bureau homicide detectives at 213-382-9470 or the LAPD's 24-hour tipline at 877-527-3247. Tipsters can also call Crime Stoppers at 800-222-8477.