Emergency services raced to the northbound carriageway of the M6 between junctions 27 at Wigan and 28 at Leyland at 11.55am following the collision between a Mercedes and a Vauxhall.
When firefighters arrived at the scene they found one car on its roof and a nearby embankment on fire.
Two people from the overturned vehicle managed to get themselves out and were treated by paramedics for minor injuries.
The driver of the other vehicle was not seriously hurt.
Traffic was affected while the motorway was closed for recovery work.