A farmer was killed when he fell asleep in his LandRover driving back from this summer’s Royal Welsh Show.
Robert Watkins, 65, died when his 4x4 hit a wall and a tree while driving the 50 mile return journy home having spent the day at the show in Builth Wells.
Mr Watkins, known locally as "Spuddy" had attended the Royal Welsh Show with friends and family.
But an inquest heard he was out with his dog at 3.30am - and had a "microsleep" at the wheel 22 hours later.
An inquest in Newport heard he was not wearing a seat belt when he was thrown across his 4x4 and his head on the windscreen.
The vehicle smashed into a concrete pillar, hit a tree and was found in a nearby field.
Grandfather Mr Watkins was pronounced dead near the Lamb and Flag pub in Abergavenny, Monmouthshire.
Forensic collision investigator Dean Burnett said Mr Watkins lost consciousness seconds before the crash at 1.40am.
The inquest heard Mr Watkins was travelling at 75mph and had been turning on a right hand bend with his foot on the break pedal.
Mr Burnett said the car had hit a grass verge and smashed into the pillar at 61mph.
A post mortem gave a cause of death as a compression fracture and dislocation of the lower cervical spine combined with trauma.
Mr Burnett said: "The conclusion I have come to is there is a level of unconsciousness and it’s a realistic possibility he suffered a microsleep.
"Had he been in that situation, if he had woken up as the vehicle left the road he wouldn’t have had time to react.
"If the seatbelt had been worn, it’s possible the collision may have been survivable."
Friend Kathryn Whitow said Mr Watkins told her he was tired before the crash because he had been up with his dog at 3.30am before travelling from his home in Monmouth to the Royal Welsh at Builth Wells.
Ms Whitow, agricultural relationship director of Barclays Bank, described him as "family orientated" and "a live stock man".
Coroner Caroline Saunders recorded a conclusion of death by road traffic collision.