From Olympic athletes kit carrier to world champion in seven years -- Dina Asher-Smith fulfilled her dream born on 'Super Saturday' at the 2012 London Games. AFP/VNA Photo

DOHA  Dina Asher-Smith became the first British woman to win a short sprint world title on Wednesday with a dominant performance in the 200m.

The 23-year-old -- silver medallist in the 100m -- led from the start to time a national record 21.88 seconds at the Khalifa Stadium.

Asher-Smith -- winning only Britain's second medal over 100/200m in the championships with Kathy Smallwood-Cook taking a bronze in the 200m in 1983 -- said she was still in shock.

"I don't know what to say, I don't think it's properly sunk in," an emotional Asher-Smith told the BBC.

"Jon (Blackie) and I knew I could do it, it means so much.

"I woke up today thinking 'this is it. This is the moment you did all your work for'. The tiredness disappeared.

"All the support means so much. For my mum, my dad and his wife to be here, it means so much.

"I'm lost for words. I dreamt of this and now it's real."

Brittany Brown of the United States took silver in 22.22sec and Mujinga Kambundji of Switzerland was third in 22.51sec.

Asher-Smith showed no signs of nerves at being title favourite bursting from the blocks to round the bend in control of the race.

Brown gave chase down the straight but the Briton never faltered crossing the line clear of the field and put her hands to her face when she realised she had also set a new British record and added the world title to the European one she won last year.

Asher-Smith had been propelled into favouritism when a whole swathe of major contenders dropped out.

The 100m world champion Shelly-Ann Fraser-Pryce was advised by her coach not to attempt the double.

Two-time defending champion Dafne Schippers was injured and Olympic gold medallist Elaine Thompson failed to show for her semi-final.

Asher-Smith -- who carried the athletes kit at the Olympics in London in 2012 and was inspired by Jessica Ennis-Hill's title in the heptathlon -- said it wasa relief to have justified her favourite's tag.

"Normally I am so chatty and full of energy but I am just lost for words," she said.

"It's one thing people saying you're the favourite but you're only the favourite if you perform how everyone expected

"It means a lot. I am happy, I am going to enjoy this and use it as motivation going into the big one (the Tokyo Olympics) next year." AFP