Tudor Simionov, 33, was attacked outside a £12.5 million Mayfair townhouse where the party was being held at around 5.30am on New Year's Day.
His girlfriend Madalina Anghel said he had only moved to Ilford, East London, from his native Romania two months earlier in search of a better life.
A 25-year-old man was arrested after handing himself in at a police station on Monday evening.
Two more men, aged 20 and 23, have also since been arrested on suspicion of murder.
The 20-year-old was arrested at a house in Brent, North West London, at around 6am on Tuesday after attempting to flee and being caught by a police dog.
The 23-year-old was arrested around the same time at a property in Hammersmith, West London.
Detectives are still appealing for information to help trace Ossama Hamed, 25, and 23-year-old Nor Aden Hamada in connection with murder.
ARRESTS FOLLOW TWO PREVIOUS CHARGES
Detective Inspector Garry Moncrieff said the murder investigation "continues to move at pace".
He said: "We now have three arrests for murder and a woman charged with perverting the course of justice and a man charged with violent disorder.
"The three men will now be questioned by investigators. However, we will not stop until we have apprehended all those who have played a part in Tudor's murder. Two other men sought remain at large.
"Ossama Hamed and Nor Aden Hamada are dangerous individuals who need to be apprehended.
"I would urge anyone who has seen them, or knows of their whereabouts, to contact police immediately.
"These are live lines of enquiry, therefore I am not willing to speculate on where they may be but rest assured we are working with colleagues to ensure that if they are in this country, or overseas, we will track them down."
A 26-year-old woman has already been charged with perverting the course of justice in relation to the case and a 25-year-old man has been charged with violent disorder.
Anyone with information regarding the whereabouts of Hamed and Hamada, or who has information that could assist the investigation, including any footage, can contact the Met 101 and quote 3276/1Jan or call Crimestoppers anonymously on 0800 555 111.
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