A city court fined Valuev 30,000 roubles and ordered the 34-year-old boxer to pay an additional 100,000 roubles in compensation after he beat a security guard outside a St Petersburg sports complex in January 2006.
Yuri Sergeyev, 61, sued Valuev, saying he had suffered serious injury after the boxer, who stands 2.13 metres and weights almost 150kg, punched him over a parking incident.
Valuev, former World Boxing Association (WBA) champion, said he had only tried to "shake off" Sergeyev after he insulted his wife Galina.
"Just imagine what would have happened to that old man if I really punched him," Valuev, who is in Berlin training for his next fight, was quoted as saying by the Russian media.
The Russian, dubbed the "Beast from the East" for his size and menacing appearance, suffered his first professional defeat and lost his WBA title to Uzbek Ruslan Chagaev in April, 2007 in Stuttgart, Germany.
Valuev is scheduled to fight Belarussian Sergei Lyakhovich in next month’s elimination heavyweight bout in Nuremberg, Germany, with the winner taking on Chagaev for the WBA crown.