The defending champion Chaz Mostert was airlifted to hospital with a broken leg after a crash that injured three volunteer officials and suspended Bathurst 1000 qualifying.
The V8 Supercars driver Mostert broke his leg and wrist in his second spectacular crash in three years at Mount Panorama, forcing seven trackside marshals to jump for safety.
One flag marshal was taken to Orange Base Hospital in a stable condition with a chest injury while two more suffered minor complaints.
The other four emerged unscathed after Mostert's Ford smashed into their trackside enclosure after pinballing off walls approaching Forrest's Elbow at up to 170km/h.
Mostert's father Eddie and partner Annie looked on in horror in the team garage during the accident.
Mostert was airlifted by helicopter to hospital - also in Orange - in a stable condition, event chief medical officer Kaaren Vinns said.
The injuries are expected to rule Mostert out for the rest of the V8 Supercars season with five rounds left.
Mostert's crash immediately suspended all racing at Mount Panorama due to the damage to the circuit's fencing.
Qualifying will be held from 2:30pm (NZ time) today with the top 10 shootout from 7:10pm (NZ time).
Mostert crashed so early in the session that no qualifying times were recorded.
"Our No.1 priority is the safety of our drivers and officials," V8 Supercars boss James Warburton said.
"Our thoughts are with Chaz and his family and the marshals who do an incredible job."
"I'd like to thank the specialist emergency response teams and medical staff at the circuit."
A spokesman for Mostert's Prodrive Racing team said the Ford young gun had been in good spirits while being transported from the track by ambulance to the waiting helicopter.
"He is receiving pain relief but is otherwise okay," the spokesman said.
"He did not lose consciousness and has been talking to family and teammates in the circuit medical centre."
It was another Bathurst disaster for Mostert.
He crashed at practice and missed qualifying in his debut in 2013.
And Mostert did not take part in last year's qualifying session after being penalised for passing under red flags.
He started the 2014 Great Race from the back of the grid but bounced back to pull off a last-to-first win with co-driver Paul Morris.
"He's just destined not to qualify for this race," Prodrive Racing team principal Tim Edwards told ths Speedcafe website.
"(But) he's in good spirits. His comment to me was 'good job we signed that contract a couple of months ago'."
Mostert had re-signed with Prodrive Racing in August until the end of 2019.
He had been the bookies' favourite to claim pole on the mountain.
The withdrawal of Mostert and co-driver Cameron Waters reduces the Great Race's field to 26.
Mostert had hoped to make a move for the championship with back-to-back wins at Bathurst, which offers double points.
He was sitting second in the V8 Championship standings at Mount Panorama, less than 200 points behind Ford team-mate Mark Winterbottom.