Brianna Rollins answered any questions about her ability to perform on the big stage when she dethroned 100m hurdles queen Sally Pearson to win gold at the world championships on Saturday.

Rollins, America's new kid on the block who celebrates her 22nd birthday on Sunday, had a terrible start and was last out of the blocks. But she drew level with defending champion Pearson of Australia by the ninth barrier and edged ahead over the final hurdle to win in 12.44 sec.

Pearson, who has had a difficult season after two hamstring injuries this year, finished second in 12.50.

Tiffany Porter of Britain was quickest out of the blocks and ran well to finish third in a personal best of 12.55.

Rollins grabbed headlines in June at the US championships when she won in 12.26, the fastest time since 1992. But her absence from the Diamond League circuit led Pearson to question how the young American would cope in the championship arena.

The 26-year-old Pearson found out first hand, immediately realizing at the finish she had lost her title.

She was first to congratulate Rollins, easily identifiable in her red, white and blue headband and still looking at the big screen in the stadium for confirmation of the win.

"I tried not to panic; I know I had a very terrible start," Rollins told a media conference.

"I just tried to stay focused on my own lane and my own 10 hurdles and finish strong," added the student from Clemson University in South Carolina, which boasts 2004 Olympic 200m champion Shawn Crawford among its alumni.

While Rollins was hitting the headlines earlier in the season with her eye-catching time, Pearson, who has dominated the technical event in recent years, was just returning from a second hamstring injury.

Famed for her smooth hurdling action, Pearson suffered defeats in three of her four Diamond League races but after finally winning in London last month she was confident of being up to form for the world championships.

The 26-year-old set a season's best in each of her three races in Moscow but at the moment of truth was not quite good enough.

"I'm satisfied. It's not gold, but it's the best I could produce tonight," she said. "In July, others were smashing me, tonight I was only beaten by one.

"I came here believing I could win the world championships - and, hey, I wasn't far off it," she said with a slight smile.

"I'm coming into shape now so I'm looking forward to my last few races to see what I can run."

(China Daily 08/19/2013 page24)