EUGENE, Oregon (AP):

Jeremy Wariner isn't invincible anymore - a point LaShawn Merritt proved once again Thursday night.

Merritt pulled his second upset of the year over the world's supposed fastest 400-metre runner, dashing away from Wariner in the homestretch to win the US Olympic track and field trials.

Starting in lane 6, one lane outside of Wariner, Merritt jumped to a slim lead about halfway through, though. Wariner does his best work in the final 150 metres. But Merritt did not let up and as they started down the backstretch, it became clear that Wariner would not make a move to catch Merritt, who finished second to Wariner at the World Championships last year.

"Coming into this, I wasn't really worried about everyone saying I wasn't the favourite," Merritt said. "In my mind, I was the favourite."

Merritt finished in 44 seconds flat, defeating the defending Olympic and two-time world champion by 0.20. Earning the third spot was national indoor champion David Neville.

Moments before, the women's 400 went much more to form, with Sanya Richards winning and Mary Wineberg and Dee Dee Trotter capturing the other two spots.

Richards is seeking an individual gold medal to go with the 1,600 relay gold she won in Athens.

"My whole motto is, 'If I didn't think I could win, I shouldn't train as hard as I do,"' Merritt said. "Point blank, nobody trains hard to be No. 2 in the world. If you're racing and get second place, you go back and train harder to be No. 1."