Former Olympic champion LaShawn Merritt of the US runs a season's best time to beat world and Olympic 400m champion Kirani James in a thrilling race at the Eugene Diamond League meeting.
Merritt started the race strongly before James from Grenada caught him in the home straight. But Merritt fought back to just edge the victory in 44.32 seconds.
The next Diamond League event in Rome will be live on Thursday on BBC Three, online, on mobile and Connected TV from 19:00 BST.
Available to UK users only.