Shamier Little redeemed herself from her disappointment in Barcelona 2012 by taking the 400m hurdles title in convincing fashion with 55.66.
The Texas A&M student, who arrived in Eugene with the fastest junior time in the world when winning in 55.07 at the NCAA Championships last month, ran evenly with Great Britain’s Shona Richards in the first half of the race but took the lead around the second bend before she entered the homestretch.
Little noticeably played it safe over the last hurdle and slowed down to avoid a repetition of the stumble that took her out of the medals in Barcelona two years ago.
With her mother cheering up from the stands, Little finished strong off the final barrier to hold off fast-finishing Richard and fellow US hurdler Jade Miller.
Richards and Miller were rewarded with British junior record of 56.16 and a personal best of 56.22 respectively.
Three other athletes set personal bests, including Zurian Hechavarria, who improved the Cuban junior record to 56.89 to finish fourth.
Javier Clavelo Robinson for the IAAF