Williams turned in a personal-best time of 12.57, taking the gold in a photo finish over Germany’s Cindy Roleder (12.59) and Belarus’ Alina Talay (12.66).
The win puts Williams makes her one of the frontrunners in the 100 meter hurdles in the upcoming 2016 Rio Olympic Games.
Williams’ sister, Shermaine Williams, also ran in the finals, clocking a 12.95, finishing in seventh place.