Olympic bronze medallist Bershawn Jackson ran the fastest 400 metres hurdles of the year on Sunday, then predicted an American sweep at the world championships in August.
"Most definitely a sweep," said the head-band wearing Jackson after his victory at the Oregon US trials in 48.03 seconds.
"We have the greatest hurdlers in the world. I don't think other countries in the world can compete with America."
Young collegian Johnny Dutch claimed second behind Jackson in the 400 hurdles with a lifetime best 48.18 with Olympic champion Angelo Taylor third in 48.30.
The 2004 Olympic gold medallist Shawn Crawford sped to a wind-assisted 19.73 seconds in winning the men's 200, while world champion Allyson Felix claimed the women's race in 22.02 seconds to set up another US-Jamaica sprint showdown in the Berlin world championships.
Dawn Harper backed up her Beijing gold medal with a wind-assisted 12.36 seconds in the women's 100 metres hurdles, but there was disappointment in the heptathlon when Olympic silver medallist Hyleas Fountain withdrew after five events with a neck injury.
Only the top three finishers in the cut-throat trials and defending world champions qualify for the American team for the August 15-23 worlds.