Yeats won gold in the 67-kilogram class, defeating local favourite Dzhanan Filipova Manolova 4-1 in the final.
Earlier in the day, she defeated Moa Lena Maria Nygren of Sweden, Kiymet Kocyigit of Turkey and Kona Suzuki of Japan.
"Dori has had a tough year filled with challenges, yet you would never know it here," said Canadian coach Leigh Vierling. "She showed such composure, pose, and grit through the tournament. She deserves to be the world champion again."
In addition to winning the junior title in 2012, Yeats also won silver at last year's senior world championships.
In the 59-kilogram class Thursday, Braxton Papadopoulos of Ajax, Ont., took silver after losing 9-3 to Tserenchimed Sukhee of Mongolia in the final.
Papadopoulos advanced by defeating Aisuluu Tynybekova of Kyrgyzstan, Anzhela Fomenko of Russia and Luisa Niemisch of Germany.
"It's very exciting to see Canadian athletes who are not afraid to step up and believe they can win on the highest stage," said Vierling. "The Mongolian wrestled a heck of a match against her. But at her age it's about learning from each experience. She will be back."
Cierra Carere of Guelph, Ont., finished 15th at 51 kilograms.