Police released CCTV footage of the incident after four men got into a violent fight shortly after midnight on September 10th.
Local media reported that two Algerians had gone to the aid of a woman who was arguing with two Serbian men.
The 37-year-old Algerian was seriously injured and died in hospital the next day. His 35-year-old friend was also stabbed but survived after several hours of emergency surgery.
The second Serbian suspect also handed himself into police on Wednesday but has since been released.
His 39-year-old friend confessed to stabbing the Algerian but said that it was in self defence. Both men fled to Serbia after the attack, and told police they decided to hand themselves in after hearing that an international arrest warrant had been issued for them and the pressure of being found became too great.
The suspected killer is now being held in police custody.
Police spokesman Thomas Keiblinger told Radio Wien that the victim may have known the woman who was arguing with the Serbians from the drugs scene. The Serbians allege that she had been harassing them, that they pushed her, and were then attacked by the Algerians.
The 35-year-old Algerian is also currently in police custody after being arrested for a drugs offence.