Police were called to a home on Jersey Street in Matraville after reports of a home invasion about 11pm on Sunday.
Officers were told at the scene that a 65-year-old woman had been approached by two men who allegedly entered the house.
One of the men allegedly assaulted a 70-year-old inside the home.
The man sustained injuries to his head and hands.
Police said the two home invaders took car keys from the home and drove away in a blue Subaru XV.
The 70-year-old was taken to Prince of Wales Hospital by paramedics in a stable condition.
The car was later found in Hebersham in Sydney’s west and will be forensically examined.
As part of their investigation, police released footage of someone they say could help their inquiries.
The footage shows a man knocking on the door, before two men exit.
They are then seen leaving the house.
Police described one of the men as being of Aboriginal or Torres Strait Islander appearance and aged in his early 20s.
He was seen wearing a black jumper and pants.
Police asked anyone who recognised the man to contact Crime Stoppers.