It was learnt that the duo who were travelling in a Myvi vehicle were on their way to Lido for supper after a night out at an entertainment outlet in Beverly Hills when the 4am incident happened.
According to the 20-year-old passenger, the attacker started to punch and stab his friend with a sharp object before fleeing with their car key which was on the ignition and a bag that contained cash.
The bag was recovered not far from the scene.
However, the cash was missing.
The injured man, who was said to be a hotel employee, sustained injuries to his face and chest was subsequently rushed to the Queen Elizabeth Hospital by paramedics who arrived moments later.