PC Harry Sage was on his way to work when he saw 90-year-old Rene laying unresponsive in the road with facial injuries.
Using his emergency lifesaving training, he managed to tilt her head and clear her airways until she started breathing again.
After hospital treatment, Rene made a full recovery and is now back home with her family.
In a letter to PC Sage, her son John said: “Words cannot express the thanks and gratitude we have for this amazing young police officer. We will never forget what he has done for our family and he deserves the best that life can offer.”