The 40-year-old was a rear seat passenger in Ford Galaxy people carrier which crashed whilst travelling south.
Police Scotland state the car struck the central rope barrier before coming to rest on the central reservation.
A spokesman said that as a result of the impact, the person who died was thrown from the vehicle onto the road where he was struck by a northbound car.
The driver of the people carrier, aged 40, and his other male passengers aged, 23, 34 and 63, were all taken by ambulance to Wishaw General Hospital suffering from minor injuries.
All have since been released from hospital.
The driver of the other vehicle, aged 26, was uninjured.
Police Scotland state: “A number of people stopped to assist those involved in the crash, however, we are still appealing to anyone who was in the area and who witnessed the crash to contact them at the Roads Policing Unit, Motherwell Police Office via 101.”
The accident happened just after 5 pm and the road was fully reopened again at 2.05 am.
There was extensive traffic disruption and the start of the scheduled Friday night greyhound racing meeting at Gretna was delayed by more than half an hour as some trainers with runners faced lengthy diversions.