Fauja Singh, from Illford in East London, finished the Toronto Waterfront Marathon in eight hours, 25 minutes and 16 seconds.
The determined participant “hot the wall” at 22 miles, but carried on for another two hours, before finishing in 3,850th place ahead of five other competitors.
Mr Singh took up running 11 years ago after his wife and son died and trains everyday by running 10 miles.
His coach and translator Harmander Singh told the BBC that Mr Singh was “overjoyed”.
“Earlier, just before we came around the (final) corner, he said, ‘achieving this will be like getting married again’.
The widower was born in India, 1911 and began life as a farmer in Punjab, before moving to Britain in the 1960s.
Mr Singh told the broadcaster that his stamina is down to ginger curry, tea and “being happy.”
He said, “The secret to a long and healthy life is to be stress-free. Be grateful for everything you have, stay away from people who are negative, stay smiling and keep running.”