Although the Hong Kong event was Singh's last competitive race, his coach said the centenarian will still run for pleasure.
"He's my best student, I would say, which is ironic because he's twice my age."
As he hangs up his running shoes, Singh told CNN he had no secret diet or training regimen. He attributed his success to a simple love of the sport.
"It's because of the happiness I get out of it. If something makes you happy, you'll do it well."