McMaster, the Gold Coast Commonwealth Games Champion, seemed in sublime form and set to win his race in comfortable fashion when he clipped the 8th hurdle and lost his rhythm and balance, causing him to lose ground.
The Virgin Islander; however, seemed settled for second when he misjudged the 10th hurdle and fell.
It is unclear if McMaster, who is set to take part in the Tokyo Olympics, has suffered any injury as a result of his tumble.
The race was eventually won by Alison Dos Santos of Brazil in a Personal Best time of 47:34.
See YouTube link to race: