NEW YORK CITY (AFP) - An American grandmother, who on Sunday was the oldest woman to compete in the New York marathon, died a day later.

She was 86.

Joy Johnson took just under eight hours to complete the 42.2km race.

She stumbled and hit her head at around the 32km mark.

She went to a medical tent only after completing the race and declined to go to hospital.

Sunday was the 25th consecutive time she had finished the race. Her fastest time in New York was just under four hours in 1991. She came first in her age group six times.

When she and her sister returned to their hotel after the event, Johnson lay down to rest and never woke up.

Just 18 of the more than 50,000 starters this year were aged over 80.

Johnson came in fourth in her group of runners aged 80 to 89.