DOHA — Nia Ali of the United States, back in the starting blocks after giving birth to her second child, stormed to victory in the 100m hurdles at the world championships here Sunday as Keni Harrison's wait for a major title continued.

Ali surged into the lead after around 50 meters to take gold in a personal best of 12.34sec at the Khalifa Stadium.

But it was more disappointment for Ali's USA teammate Harrison, the world record holder who is still to win a world or Olympic title. Harrison took the silver in a time of 12.46sec while Jamaica's Danielle Williams won bronze in 12.47sec.

The US was denied a possible podium sweep when Olympic champion Brianna McNeal was disqualified in the opening heats after a false start.

Muhammad wins second gold as US romp to 4x400 gold

Dalilah Muhammad bagged her second gold medal of the World Championships on Sunday as the United States cruised to victory in the women's 4x400m relay.

Muhammad, who set a world record en route to her 400m hurdles gold on Friday, ran a blistering third leg for the USA who won in a time of 3min 18.92sec.

Poland took silver in 3:21.89 while Jamaica pipped Great Britain for bronze in 3:22.37.

The USA victory also sees Allyson Felix extend her record tally of world championship gold medals.

The 33-year-old American, who did not run in the final but featured in the early rounds, now has 13 gold medals. — Agencies