Anthony Adams, of Stockwell, south-west London, was attacked in an alleyway near Brixton tube station at 2.55am. He tried to escape but was attacked again outside the station and stabbed repeatedly.
Ambulance staff treated him on the pavement but he was later pronounced dead at King's College Hospital.
A police spokesman said: 'Police are looking for two or three black suspects, all believed to be in their early twenties, who are believed to have made off in a silver or grey Metro. We would like to hear from any witnesses who may have seen an argument or witnessed a fight near the tube station.'