The 18-year-old man is from the Norwich area and has been detained for questioning, Norfolk Police said.
The first person arrested on Monday, a 16-year-old boy also from the Norwich area, remains in custody.
The stabbing victim, Tafadzwa Kahn, was from St Giles Street in Norwich.
The attack happened shortly after midnight at a private party in Long Lane on March 18.
Mr Kahn, known as Taffy, was stabbed following an argument and pronounced dead at the scene by paramedics shortly after they arrived. Read More