Men's and women's steeplechase and 5,000-meter prelims also got underway on Monday night.
Ashton Eaton sets a decathlon world record on the second day of competition.
Fifteen men break 28 minutes in the 10,000m on a rainy night at the Prefontaine Classic.
Check out photos of a few fantastic finishes from last weekend's exciting action in Eugene.
Montano takes women's race; Coburn wins women's steeplechase.
All the top contenders advance to tomorrow's semifinals.