Jamaica’s Shelly-Ann Fraser-Pryce narrowly held off Dafne Schippers of the Netherlands to retain her 100m world title in Beijing.
Fraser-Pryce, 28, started strongly but was almost caught by Schippers on the line as she crossed in 10.76 seconds.
It was a sixth career gold at the World Championships for Fraser-Pryce, who won the 100m and 200m double in 2013.
Schippers, a heptathlete bronze medallist two years ago, finished ahead of American Tori Bowie in third.
It was a national record for 23-year-old Schippers, who only committed to sprinting in June, while Bowie, 24, herself a former long jumper, collected her first major medal.
Fraser-Pryce, the fourth quickest woman of all time over 100m, expressed disappointment at not breaking her personal best of 10.70 seconds.
“I’m getting tired of 10.7s. I just want to put a good race together and hopefully in the next race I get the time I’m working for,” she told BBC Sport.
“I definitely think a 10.6 is there. Hopefully I will get it together.”
Lavillenie beaten as Cheruiyot takes 10,000m gold
The 21-year-old’s first-time clearance at 5.90 metres put pressure on the French favourite, who jumped 6.05m earlier this year but had to settle for bronze here after three failures at the same height.
Germany’s Raphael Holzdeppe cleared 5.90m on his third attempt but could not improve when the bar was raised to 6m, leaving Barber – whose father George competed in this event at the World Championships in 1983 – with his first global title.
Vivian Cheruiyot won Kenya their first gold of these championships as she kicked off the final bend to hold off Ethiopian rival Gelete Burka in a slow, tactical 10,000m final.
Ezekiel Kemboi , Conseslus Kipruto and Brimin Kipruto bringing home a Kenyan 1-2-3 in the steeplechase a few minutes later.
Columbia’s defending world champion Caterine Ibarguen retained her triple jump title with a fourth round 14.90m, with no other athlete going past 14.78.
But there will be no gold this summer for Keshorn Walcott , Trinidad’s 22-year-old Olympic javelin champion, who crashed out in qualifying with a best throw of 76.83m.
Briton Yousif into 400m final as Child battles through
Yousif, who came to Britain from Sudan 13 years ago and has an English wife, improved dramatically on his first-round performance as others who had lit up the heats struggled 24 hours on.
Team captain Martyn Rooney had set a new personal best of 44.45 in the heats but, perhaps tired, he was unable to reproduce that run and came home sixth in the third semi-final in 45.29, Olympic champion Kirani James (44.16) and Botswana’s Isaac Makwala (44.11) the most impressive semi-final winners.
Eilidh Child made it through to the final of the 400m hurdles as a fastest loser as Meghan Beesley went out, while Britain’s Asha Philip exited the 100m at the semi-final stage and Kate Avery came home 15th in the 10,000m in 32:16.19.
Earlier, Britain’s Greg Rutherford reached the long jump final, while Christine Ohuruogo qualified for the 400m semi-final.