Firefighters were told that a Honda Civic, heading towards Bagshot, hit the central reservation and a lamppost near Bracknell Leisure Centre.
It then crossed to the other side of the road landing onto the bonnet of a convertible Audi A5, containing a family of three, and then bursting into flames.
The crews were called to the scene at about 11pm, and by the time they had arrived, everyone involved in the accident had been pulled from both cars.
Firefighters tackled the fire with two hose reels, but also administered first aid along with paramedics, spending more than an hour there.
The family in the Audi A3 escaped with minor injuries but the driver and passenger in the Honda Civic were taken to Royal Berkshire Hospital with leg injuries.
Bracknell firefighter Rob Evans said: "None of the passers-by stopped to take any of the credit.
"Without them this accident would have been a lot more horrific."
Police closed the road between the leisure centre roundabout and the roundabout next to the Harvester restaurant for about three and a half hours while the incident was ongoing.