British woman claims world indoor title on Sunday in a British record of 3:58.53 as Mariano Garcia of Spain wins men's metric mile.

British fans endured a nervous few minutes of running on Sunday night at the World Indoor Championships as Georgia Hunter Bell found herself several seconds behind runaway leader Birke Haylom in the middle of the women's 1500m final.

But there were sighs of relief at the bell when Hunter Bell caught and passed the Ethiopian, before coasting around the last lap to win in a British record of 3:58.53, beating Laura Muir's 3:59.58.

"This time last year I was working in tech sales and now I'm a world champion!" she said.

Haylom faded to fifth in 4:01.34 as Jess Hull of Australia took silver in an Oceania record of 3:59.45 with Nikki Hiltz of the United States third in a PB of 3:59.68.

Such was the standard, Agathe Guillemot ran a French record of 3:59.71 but was only fourth.

Should we ever have doubted Hunter Bell?

"I'm very in tune of what the pace feels like when it comes to running sub-four and I felt she could come back to me," said Hunter Bell.

When Haylom went through 800m in 2:05.30 – faster than the men's race earlier in the evening – she already had a lead of more than three seconds over Hunter Bell and the main pack.

At 1000m Haylom clocked 2:38.73 and her lead was reducing narrowly with Hunter Bell taking responsibility to drag the group back.

Hunter Bell took the lead at the perfect time, passing the fatigued Haylom at the bell, before storming home in emphatic fashion.

"It's such a relief as I felt I was in such physical shape," said Hunter Bell, "but it was mentally hard to come in as the favourite and manage to win.

"I'm really proud of myself as I was really calm and composed. I thought 'why am I stressing? I know I can do this. I just have to commit."

There was a surprise in the men's 1500m when Mariano Garcia of Spain led almost all of the way to win in 3:39.63 from world outdoor champion Isaac Nader of Portugal.

Garcia passed 800m in a pedestrian 2:05.58 but then wound up the pace and held off Nader on the final lap, the Portuguese runner clocking 3:40.06 as Adam Spencer of Australia was third.