|World Athletics Championships|
|Venue: Beijing National Stadium, China Dates: 22-30 August|
|Coverage: Live on BBC TV, Red Button, Radio 5 live, online, mobiles, tablets and app. Click here for full details.|
Kenya's Julius Yego, who refined his javelin technique watching YouTube videos, says his World Championship gold medal was "really unbelievable".
At 5ft 9ins, the 26-year-old is relatively diminutive in the sport, but he threw 92.72m - a Commonwealth record - to win the competition by nearly four metres.
"I had a serious injury and thought I won't compete in Beijing," he said.
"Very few athletes have done what I have done."
The 85kg Commonwealth champion, who initially hoped to join the ranks of famous Kenyan runners, has improved his technique after watching videos of Jan Zelezny of the Czech Republic and Norwegian Andreas Thorkildsen, who both won Olympic and world titles.
"There will not be another YouTube athlete coming through," he added. "I want to go back and watch my throw, it was almost perfect."
Earlier in the day, it was announced his team-mates Joyce Zakary and Koki Manunga had tested positive for doping at the championships. Thirteen Kenyan athletes are currently serving suspensions for doping offences.
Yego said: "I can't dwell on that, it's a shame. I always believe you can win clean. In sport you win clean."
Police force to javelin thrower
According to his IAAF profile, Yego is the fourth born in a family of seven and hails from the Kenyan region of Nandi South County.
Yego had initially been recruited by the police near Nairobi, with the head coach of the national force, Nicholas Kilisio, claiming he influenced his career from an early age.
"We saw the talent in him and decided to take him. He had a small frame but we have bulked him up," said Kilisio.
Career blossoms thanks to a Finn
After winning national junior titles, Yego was selected to represent Kenya at the 2010 African Championships, where he won bronze.
His career then took off when he met Finnish javelin coach Petteri Piironen, who also looks after world silver medallist Ihab El Sayed of Egypt.
The Kenyan travelled to Finland on an IAAF scholarship, initially for two weeks in the winter of 2011-12 - where temperatures fell to about -30C.
"He had been throwing 78m, so I knew if he could throw that without a coach he must be talented," said Piironen in 2013.
"He was quite explosive, had a good upper body, but he was quite weak in the legs and I had to change some technical things."
He was selected as Kenya's only field athlete in a team of 44 at London 2012. Despite finishing 12th, he set a new national record of 81.81m.
Improvement was seen at the 2013 World Championships in Moscow, where Yego narrowly missed out on bronze after throwing 85.40m.
But a year later, he did win his first major title when he threw 83.87m to win the Commonwealth gold in Glasgow - the first Kenyan to win a field event at the Games.
|Six furthest throws in history|
|98.48m - Jan Zelezny, May 1996||94.64m - Jan Zelezny, May 1996|
|95.66m - Jan Zelezny, August 1993||94.02m - Jan Zelezny, March 1997|
|95.54m - Jan Zelezny, April 1993||93.09m - Aki Parviainen, June 1999|
Pundits on Yego
Allison Curbishley on BBC Radio 5 live:
"Julius Yego is on billboards everywhere in Kenya. If he was a legend already in Kenya he's now elevated himself to a global icon.
"He will enjoy every moment of this. Another medal for Kenya - they are taking over the world."
Denise Lewis on BBC Sport:
"This was fantastic for his country. It's quality when you see so much power go through a singular point in the javelin.
"It's a great story of determination and eagerness to learn."
Other Kenyan successes this week
Kenya are top of the medal table with six golds and 11 medals in total - here are the country's other title winners:
Hyvin Kiyeng Jepkemoi - women's 3,000m steeplechase
David Rudisha - men's 800m
Nicholas Bett - men's 400m
Ezekiel Kemboi - men's 3,000m steeplechase
Vivian Jepkemoi Cheruiyot - women's 10,000m