Rollins equals fourth-fastest hurdles time

Finally catching an allowable wind, the 21-year-old U.S. collegiate record holder sent a strong message to Australian Olympic and world champion Sally Pearson with the fastest time since 1992.

Only Bulgarian Yordanka Donkova, whose 1988 world record is 12.21 seconds, and compatriot Ginka Zagorcheva, the former record holder, have run faster. Donkova has done so twice.

"I just feel so overwhelmed, so emotional. It is so amazing," said Rollins, who previous best was 12.39 seconds at the U.S. collegiate championships.

The time, run with an aiding wind of 1.2 seconds, exceeded Pearson's 2011 world championship best of 12.28 seconds and three times world champion Gail Devers' American record of 12.33 seconds.

"Looks like I am bringing my A++ game to worlds this year," Pearson tweeted after the stunning run.

Asked whether she thinks breaking the record is possible, Rollins, whose previous season best was 12.70 seconds, answered: "I don't know. We'll see," "I don't know. We'll see," said the former Clemson University student, whose best before this season was 12.70 seconds.

Lured to athletics as a teenager "because someone told me I was fast," Rollins selected the hurdles "because I thought it was interesting and fun to do."

Runner-up Queen Harrison (12.43 seconds), third-place finisher Nia Ali (12.48) and Beijing Olympic winner Dawn Harper, who has a wild card entry, also made the American team for the Aug 10-18 world championships in Moscow.

There were season-leading performances in the men's 400 metres hurdles and women's high jump finals on a hot and windy day.

Olympic silver medallist Michael Tinsley became the first man to dip under 48 seconds in the 400 hurdles this season, running 47.96 seconds, and Brigetta Barrett, the London high jump runner-up, cleared 2.04 metres (6 feet, 8.25 inches).

Former world champions Kerron Clement (48.06) and Bershawn Jackson (48.09) joined Tinsley on the U.S. team for Moscow.

Teenage sensation Mary Cain, just 17, also made the team, finishing second to teammate Treniere Moser with a gutsy run in a slow women's 1,500 metres.

Beijing gold medallist LaShawn Merritt dominated the men's 400 metres final, winning in 44.21 seconds, but London women's winner Sanya Richards-Ross was a casualty of the cut-throat trials, missing out on a place in the individual 400m.

Running in sneakers to lessen the pain from recent big toe surgery, the American record holder finished sixth in 51.92 seconds. Natasha Hastings won the race in 49.94.

World record holder Ashton Eaton played it safe but still won the decathlon with 8,291 points.