Norway's Karsten Warholm retained his 400m hurdles World Championship crown with a barnstorming victory in Doha Monday as Russia's Mariya Lasitskene completed a superb high jump hat-trick.

After an opening three days of competition marked by swathes of empty seats, Warholm delighted the biggest crowd of the championships so far with a battling victory at the Khalifa Stadium.

Warholm took gold in 47.42seconds, with his rival Rai Benjamin of the United States claiming silver in 47.66sec. Qatar's Abderrahman Samba took bronze in 48.03.

The 23-year-old Warholm roared, pumped his fist and slapped his chest as he was introduced to the crowd before the start of the race as part of a dazzling light display.

That set the tone for a classic hurdles battle, with Warholm timing his move to perfection to take the lead heading into the home straight before holding off Benjamin.

"This was a very tough race," Warholm said. "I actually felt my heart was going to stop. I thought 'I'm going to die but it's going to be worth it'."

Although Monday's crowd was the largest of the championships so far, most fans had left the arena well before Warholm set off on his lap of honour.

"I'm used to talking to myself so it wasn't a problem," Warholm joked.

"It was something else in London (in 2017) when there was 60,000 people there. I've got to be honest about that. But at the same time, with the gold medal, I couldn't care less."

Warholm's win came just moments after high jump Lasitskene won a third consecutive world championship title to set alongside her wins in 2015 and 2017.

The 26-year-old, who is one of only 30 Russian athletes allowed to compete in Doha under the authorised neutral athlete banner, took gold ahead of Ukraine's Yaroslava Mahuchikh.

Career milestone

Lasitskene claimed the gold after clearing a height of 2.04m to win on countback ahead of Mahuchikh.

Vashti Cunningham of the United States took bronze.

The win marked another career milestone for Lasitskene, who has dominated international high-jumping in recent years.

"It was like in a fairytale to get a third world title," Lasitskene said. "My whole country expected me to be on the podium. I had to cope with this pressure."

Lasitskene was barred from the 2016 Olympics after Russia was banned from the games over the country's doping scandal.

But she has since been allowed to compete as a neutral athlete, a status handed to athletes who are deemed to be above suspicion by the International Assocation of Athletics Federations.

There was also success for another defending champion in the 5,000m, where Ethiopia's Muktar Edris retained his 2017 crown in a time of 12 minutes 58.85 seconds.

His compatriot Selemon Barega, 19, took silver in 12:59.70 and Canada's Mohammed Ahmed the bronze in a time of 13:01.11.

Also on the track Monday saw African runners claim victories in the women's 800m and women's 3,000m steeplechase.

Uganda's Halimah Nakaayi took advantage of the absence of defending champion Caster Semenya to win the 800m, conjuring a sprint finish to take gold in 1min 58.04sec, with the fast-finishing Raevyn Rogers of the United States taking silver in 1:58.18.

Sweet redemption

American Ajee Wilson had to settle for bronze in 1:58.84.

The 800m at this year's championships took place without South Africa's two-time Olympic champion Semenya, prevented from competing in Doha after losing her legal battle against regulations which would have forced her to take medication to lower naturally elevated testosterone levels.

The 3,000m steeplechase meanwhile saw redemption for Kenya's Beatrice Chepkoech, who won gold two years after a blunder cost her a medal in London.

The 28-year-old world record holder pulled clear from the field early on and led by around 40 metres at the bell before coasting home in 8min 57.84sec.

Defending champion Emma Coburn of the United States took silver with a time of 9:02.35 ahead of Germany's Gesa Krause, who claimed bronze in 9:03.30.

Chepkoech had missed out on a medal two years ago when she inadvertently missed a water jump and was forced to backtrack before finishing fourth.