The crash, which occurred during qualifying, required immediate and urgent attention from race officials and an ambulance.
Mostert is the reigning champion of Bathurst, but this crash will likely be the end of his champion defence with early updates suggesting he badly broke his leg and wrist in the crash.
If he can somehow recover in time for Sunday's race, he will be forced to defend his crown from the pit lane, and his team will be forced to undergo a monstrous job to repair his car to race standard.
He was communicating well after the crash while receiving medical attention.
He will be taken to hospital via helicopter.
Our thoughts are with Chaz at this difficult time.
REPLAY - Chaz Mostert - Monster Crash #Bathurst1000 http://t.co/DYQdD0boe5
— V8 Supercars (@v8supercars) October 9, 2015Friday's qualifying action was called off soon after the crash.