Four gang members were arrested in Meadowlands, Soweto, on Wednesday after being found with R100,000 worth of stolen goods, said police.
The men, aged between 20 and 33, were caught when a stolen cellphone was traced to a street in Zone Eight, said Constable Sibusiso Chauke.
Police saw a black BMW there matching the description of a car used in a house robbery in Glen Vista in which four robbers stole cash and goods, said Chauke.
When police ordered the driver to pull over, a man opened the door and pulled out a firearm, he said.
"Police opened fire and wounded the man." He was under police guard in the Chris Hani Baragwanath Hospital.
It was later established that the man was carrying a toy gun, said Chauke.
The three other men would appear soon in the Johannesburg Magistrate's Court.