BBC Sport picks the athletes and races to watch at Saturday's Diamond League meeting in the US city of Eugene, Oregon.
It is a battle of the heavyweights in the men's 400m as world champion LaShawn Merritt, 27, renews his rivalry with Olympic champion Kirani James, who finished a surprising seventh in last year's World Championships.
Organisers have called this their "best ever" women's 1500m field, with world champion Abeba Aregawi taking on reigning world 800m champion Eunice Jepkoech Sum. Brits Hannah England and Laura Weightman are also be competing.
Available to UK users only.