American Bryan Clay cruised to decathlon gold after a devastating display over two days to finish with 8791 points in Beijing.
The former world champion ran the final event, the 1500m, needing to avoid being beaten by a massive one minute.
Belarussian Andrei Krauchanka won silver, and Cuba's Leonel Suarez squeezed through to grab bronze.
Clay, 2004 Olympic silver medallist and 2005 world champion, beat Krauchanka by 240 points - the highest winning-margin since 1972.
Russia's Alexander Pogorelov was fourth, while Roman Sebrle of the Czech Republic, the reigning world and Olympic champion, finished sixth.