Dina Asher-Smith has seized her chance to win the 200 metres at the world athletics championships in Qatar and become the first British woman to claim a global sprint title.

Asher-Smith proved the class act in the field, powering home in a national record 21.88 seconds to add gold to the silver she won in the 100m.

The victory doubled Britain's medal tally at the championships to two, both coming from Asher-Smith, and the 23-year-old has already turned her attention to next year's Olympics in Tokyo.

"Doing well in Doha was part of the plan and in thinking about Doha you're thinking about the Olympics as well," the Londoner said.

American Brittany Brown grabbed the silver in 22.22 while Switzerland's Mujinga Kambundji completed the podium by claiming bronze in 22.51.

Grant Holloway of the United States blazed to his first 110 metres hurdles world title in a dramatic race in which defending champion Omar McLeod of Jamaica fell.

The 21-year-old smoothly glided over 10 hurdles to cross the line in 13.10 seconds, five hundredths of a second ahead of 2015 world champion, Sergey Shubenkov of Russia with bronze going to European champion Pascal Martinot-Lagarde of France.

Poland's Pawel Fajdek, the undisputed king of hammer throw, sealed his fourth consecutive title with a throw of 80.50 meters.

Frenchman Quentin Bigot took the silver with 78.19, beating Hungary's Bence Halasz by a single centimetre.

After his latest victory, the Pole wasn't thinking about next year's Tokyo Games but instead was eyeing a fifth world crown in Eugene, Oregon in 2021.

"Taking a fourth world title, it is very emotional for me and I feel very proud tonight," said Fajdek.

"Now, next hard work in the following two years until Eugene."

Michael Norman, the fastest 400 metres runner of the year and hot gold medal contender, said his body gave up on him as he went out in the semi-finals.

The 21-year-old American finished last in 45.94, two and a half seconds slower than his season-best 43.45, jogging across the finish line after looking fully fit the previous day when he won his heat.

"Running down the back stretch, my body was giving me warnings. Instead of ignoring them, I listened to them. Every track athlete knows these warnings, when something doesn't feel right. I think I made the mature athlete choice," he told the BBC

Steven Gardiner of the Bahamas led the way into Friday's final with 44.13 from 2012 Olympic champion Kirani James of Grenada (44.23) and USA's Fred Kerley (44.25).

Canadian season-leader Damian Warner holds the overnight decathlon lead, 27 points clear of compatriot Pierce Lepage and 30 ahead of world record holder Kevin Mayer of France.

Britain's Katarina Johnson-Thompson tops the heptathlon by 96 points over the world and Olympic champion Nafissatou Thiam of Belgium.