The 39-year-old is recovering in hospital after the brawl erupted at 12.20am and a knife was pulled.
Detectives investigating the attack said a 33-year-old man has been arrested on suspicion of attempted murder.
A Met spokesperson said: “He was taken to a central London police station where he remains at this time.”
The incident took place at the junction between Victoria Street and Carlisle Place in Westminster. Paramedics found the victim with stab wounds and he was rushed to a west London hospital.
Doctors have confirmed his condition is not life threatening.
A crime scene remains in place opposite Victoria Station.
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