KudinovWins Gold in 25km Open Water Swim
Kudinov, who also won the 25km gold at last year's first-ever open water world championships in Hawaii, surged ahead from the 23.5km mark and eventually crossed the finish line at Momochihama Beach in five hours, 25 minutes and 32 seconds, Reuters said.
Frenchmen Stephane Gomez and Stephane Lecat took silver and bronze respectively after challenging Kudinov in a three-way battle over the final five kilometers at the Hakata Bay course.
"It feels amazing to win the gold medal, but to tell you the truth I'm too exhausted to speak right now," said Kudinov.
Gomez finished 25 meters behind the Russian in 5:26:00, while Lecat clocked 5:26:36 after tiring over the last 800 meters.
In the final event of the open water swimming, the competitors completed a half circuit of offshore Nokono Island before doing a U-turn at the 12.5km point.
American Mark Leonard led through the midway point of the race, but faded badly over the second half to finish sixth.