Kenenisa Bekele out-sprinted his mentor Haile Gebrselassie to head up a clean sweep of medals for Ethiopia in the men's 10,000m in Paris.
The 21-year-old stuck with Gebrselassie throughout the race before powering past his team-mate over the last 150m to steal victory in 26 minutes 49.58 seconds.
Sileshi Siline completed the hat-trick of medals for Ethiopia as he came home in third place.
Defending champion Kenya's Charles Kamathi had tried to stick with the trio but he was beaten by the pace and slipped down the field.
"Haile was a great champion and it is a real honour to succeed him as Ethiopian number one," said Bekele.
Gebrselassie, who is dubbed the Emperor, was bidding for his fifth world title but he was delighted to settle for silver behind his fellow countryman.
"It was more important to beat the Kenyans and we did that effectively," he said.
"I am happy with the silver because last time I lost the title to the Kenyans and that was not a happy experience for me."
The Ethiopian trio stuck to their plan rigidly and set a lightning pace, producing 61-second laps as they contrived to push the threatening Kenyans, led by Kamathi and Salim Kipsang, out of the race.
Gebreselassie went to the front after 10 laps and though he moved to the outside to allow Bekele to pick up the lead, his young training partner resisted, prefering to launch his attack from behind.
Bekele moved up to the Olympic champion's shoulder with 150m to go and sprinted clear of Gebreselassie, who could not find enough to chase him right down to the line.
The new world champion is now set to challenge another strong field in the 5,000m - an event where he has posted the third fastest time this year, though he admitted he has not made a final decision.
"My main aim was to win the 10,000m title and I don't want to think about the 5,000m yet," he said.
Gebreselassie may have seen his crown passed on to his heir apparent in Paris but that is unlikely to stop him defending his Olympic title next year before he moves on to the marathon.
"I am going to carry on because even though I was beaten the time I ran was good enough to give me confidence for the future," he revealed.
"There are many possibilities for Bekele, he is already outstanding but I will still try and find a way to beat him."
Men's 10,000m results
1. Kenenisa Bekele (Eth) 26:49.57
2. Haile Gebrselassie (Eth) 26:50.77
3. Sileshi Sihine (Eth) 27:01.44
4. Abdullah Ahmad Hassan (Qat) 27:18.28
5. John Cheruiyot Korir (Ken) 27:19.94
6. Wilberforce Talel (Ken) 27:33.60
7. Salim Kipsang (Ken) 27:45.05
8. Kamiel Maase (Ned) 27:45.46
9. Karl Keska (Gbr) 27:47.89
10. Ismal Sghyr (Fra) 27:54.87