The incident occurred in the town of Chernyakhovsk during open-air celebrations for the last day of Maslenitsa, or Pancake Week, on Sunday. The event, which attracted thousands of people, also involved a theatrical show and horse riding, Komsomolskaya Pravda reported.
Boris Isayev, 48, fell to his knees and died on stage while receiving first prize in the pancake-eating competition, an eyewitness told the daily.
"It was so unexpected," Yelena said. "He started gasping for breath and foam came out of his mouth.
"We have seen people fainting [during such contests] before," she added.
Doctors were unsuccessful in their attempts to resuscitate the man.
"He must have choked," Yelena suggested. "We probably shouldn't eat so much, even during Maslenitsa. Everybody in the town is talking about this."
Maslenitsa is of both pagan and Christian origin. It is celebrated both as a sun festival marking the end of the winter, and as the last week before Lent.
The celebrations continued after Isayev's body was taken away in an ambulance, and a winter dummy was burnt in a symbolic farewell to the coldest months of the year, the paper said.