KTM rider Toby Price (pictured) has crashed heavily in Stage Four of the 2017 Dakar Rally, the off fracturing the rider's left femur and ending his title defence.
The Red Bull racer was subsequently airlifted to hospital for medical treatment.
An ABC news report said the crash occurred around 150 kilometres from the Stage Four finish line, on a 521 kilometre day that stretched from north-western Argentina into Bolivia. The challenging region is essentially desert, with sandy, rocky terrain and, in some sections, deep chasms.
Price became the first Australian in history to win the Dakar Rally last year. After triumphing in Stage Two of this year's event, the 29-year-old was attempting to claw back a deficit lost in Stage Three when the accident happened.
The withdrawal saw Austria's Matthias Walkner (KTM) take the Stage Four win, with Chile's Pablo Quintanilla (Husqvarna) grabbing the overall lead.
Dakar competitors will next turn their attention to Stage Six, an extremely varied 692 kilometre route that stretches across Bolivia's high plains, or altiplano.
The thin air will add an extra layer of complexity to the battle, while two sections of dunes will push the riders to their limits towards the end of the stage.
Check back soon for further Dakar Rally updates.
Results Stage Four (San Salvadore de Jujuy – Tupiza: 416km timed, 521km total)
1. Matthias Walkner (AUT), KTM, 4:57:22 h
2. Xavier De Soultrait (FRA), Yamaha, +5:58 min
3. Stefan Svitko (SVK), KTM, +8:33
4. Pablo Quintanilla (CHI), Husqvarna, +9:22
5. Gerard Farres Guell (ESP), KTM, +10:24
Standings after four of 12 stages
1. Quintanilla, 12:54:02 h
2. Walkner, +2:07
3. Svitko, +5:52
4. Sunderland, +6:12
5. Farres Guell, +12:02