Peru striker Paolo Guerrero twisted superbly to head the winner for the Libertadores Cup holders on the half-hour mark to the delight of some 20,000 Corinthians fans in Toyota.
Corinthians, the first team since 1978 to win South America's premier club competition without losing a game, survived a second-half onslaught from Egypt's Al-Ahly to advance.
Chelsea, whose defence of their Champions League title ended in the group stage last week, will face Mexico's Monterrey in the second semi-final in Yokohama on Thursday.
European sides have won the last five editions of the Club World Cup, Barcelona lifting the trophy in 2009 and 2011.
Around 15,000 fans have made the long trip from Brazil to cheer on Corinthians, the first winners of the FIFA competition in 2000.
(Reporting by Alastair Himmer; Editing by Julien Pretot)
- Sports & Recreation
- Paolo Guerrero