The 29-year-old Russian, who is only the second man to successfully retain the modern pentathlon title at the Olympic games, said that winning gold in Athens in 2004 was "definitely easier" than in Beijing.
The silver and bronze medals went to Lithuanian teammates, Edvinas Krungolcas and Andrejus Zadneprovskis.
The modern pentathlon, which is often referred to as a 'true Olympic sport' is supposed to replicate a soldier delivering a message with five sporting events, pistol shooting, fencing, swimming, show jumping and running.
With three days left of Olympic competition, Russia is currently ranked 4th in the overall medal standings with 16 gold, 16 silver and 19 bronze medals, while China tops the standings boasting 46 gold, 15 silver and 22 bronze medals.
