Kori Carter of the US celebrates after winning the gold medal of women's 400 meters hurdles at World Athletics Championships in London Stadium, London, Britain on August 10, 2017. [Photo/Agencies]

LONDON - Underdog Kori Carter made a surprising lane nine move to bag the gold in women's 400m hurdles at the IAAF World Championships here on Thursday.

"I am on top of the world right now, which is a blessing. This is just an incredible feeling like I have never experienced," said Carter after her unexpected victory.

Carter clocked 53.07 seconds to upset Olympic champion and her American compatriot Dalilah Muhammad, and two-time defending champion Zuzana Hejnova of Czech Republic.

"I really wanted to win, but I've had so many ups and downs this season. To come out with a silver, I'm proud of that," said Muhammad.

"I always go out to win, but I'm just happy to even get on the podium," she added.

Muhammad claimed the silver medal with 53.50 seconds. Ristananna Tracey of Jamaica took away the bronze with a personal best of 53.74 seconds.

"I kicked it too much at the start and I was missing the energy in the last meters. I feel sorry for my performance tonight," fourth-palced Hejnova pointed out.