Sunday's victory, Christopher's second in as many weeks, also set a Canadian record. His winning time of 44.72 seconds bested the old mark of 44.86 established by Shane Niemi of Kamloops, B.C.
"When I saw the time I was shocked," Christopher told The Canadian Press from Brazil. "It was so hot and humid here that it felt like I was running in sand.
"I surprised to hear how fast my splits where, and even more surprised to hear that I ran 44.7."
Christopher nearly made history last weekend when he won the Rio Grand Prix in 44.88.
Davian Clarke of Jamaica (44.92) was second Sunday, while Leonard Byrd of the United States (45.09) finished third.
with files from Canadian Press
