Torrential rain fell from start to finish as three titles were claimed by athletes from three different continents.

Norway's Karsten Warholm responded best to the conditions to win the men's 400m hurdles and Gong Lijiao of China triumphed in the women's shot put.

It was the finale which provided the greatest moment of drama.

Francis, a 4x400m relay gold medallist at Rio 2016, had never won a global individual medal before tonight and, for most of the race, third place seemed to be as good as it would get.

Bahamas' Olympic champion Miller-Uibo powered through the first half of the race and entered the final straight with a big lead over the United States Allyson Felix, chasing a record 10th IAAF World Championship gold medal.

Felix, the gold medallist at Beijing two years ago, was slowly narrowing the gap, but did not look powerful enough to overtake the powerful leader.

Then, inexplicably, Miller-Uibo lost all momentum with the finish line at her mercy, swaying her arms and legs as if she was running through treacle before nearly coming to a halt.

It was Francis, rather than Felix, who burst through to win in a personal best of 49.92sec.

Salwa Eid Naser, born in Nigeria to a native mother and a Bahraini father, finished superbly to snatch a superb silver for the Gulf nation in a national record 50,06.

Felix won her 14th World Championship medal with bronze, in 50.08, as Miller-Uibo laboured across the line fourth in 50.49.

It was not immediately clear if she was injured, or simply fatigued.

"At the finish line I was surprised, I thought I was second or third, but then they told me, 'You are first'," said Francis.

"That is crazy."

Warholm has long been a rising star of Norwegian and European athletics but it was still expected to be far too soon for a senior global crown.

The weather, however, was always going to be an equaliser, and the Norwegian was used to stormy conditions having learned his craft training on his home island of Dimnøya off the western coast.

He was initially a multi-eventer, winning the 2013 octathlon at the 2013 World Youth Championships in Donetsk, before turning to the 400m hurdles.

The 21-year-old held a huge lead over the rest of the field coming into the home straight.

American Olympic champion Kerron Clement was gradually closing the gap and looked set to pass him approaching the final hurdle.

Warholm, though, cleared the final barrier best before powering clear to win in 48.35 - two hundredths of a second faster than his time when winning gold at this year's European Under 23 Championships in Bydgoszcz. 

"Thank you, London! I truly don't believe it," he said.

"I've worked so hard for this but I don't know what I have done. 

"This is an amazing feeling."

Cuban-born Yasmani Copello, now representing Turkey, won the silver medal in 48.49 to improve upon his Olympic bronze at Rio 2016.

Clement, world champion in Osaka 2007 and Berlin 2009, settled for third today in 48.52.

Gong also overcame terrible conditions to earn the women's shot put gong and take the first major victory of her career.

The 28-year-old Olympic silver medallist threw her arms in the air in triumph after a throw of 19.94 metres in the fifth round.

It followed silver at her home World Championships in Bejing two years ago, as well as bronze medals in Berlin in 2009 and Moscow in 2013.

There was drama behind her as Hungary's Alita Marton saved her best for last by producing a sixth round mark of 19.49m.

This moved her up from fourth and consigned United States' Olympic champion Michelle Carter to third, with 19.14m.

Huang Zhihong was the last Chinese winner of the event at the 1991 World Championships in Tokyo.

"It is 26 years since China won a shot put medal, so it's a very special moment for me," said Gong. 

"Of course, the rain affected the competition and that is the reason we didn't go past 20 metres tonight."

The US have now won four gold, five silver and six bronze medals.

Kenya remain second on three gold, one silver and three bronze.

South Africa remain the only other nation to have won more than one gold medal.

They have won two and also two bronze.