Paolo Guerrero snatched a 69th-minute winner as South American champions Corinthians stunned Chelsea to win soccer's Club World Cup on Sunday.
Chelsea, who had been under pressure to win the tournament after becoming the first holders to exit the Champions League at the group stage, missed a string of chances to lose the final.
"It's an incredible feeling," Guerrero told reporters after his goal sparked wild celebrations among the more than 15,000 travelling Brazilian fans among the crowd of 68,000.
"To win in front of so many Corinthians fans who came all this way. It's tremendous, unbelievable."
Gary Cahill, sent off in the last minute, Fernando Torres and Victor Moses were denied by brilliant saves from Corinthians goalkeeper Cassio in a game the English side largely dominated.
Corinthians, who won the first Club World Cup in 2000, caught Chelsea cold when Peru striker Guerrero headed home from close range after Danilo's shot looped up off Cahill's boot.
"We're coming away with that bad feeling after creating enough chances to at least draw the game," said Chelsea captain Frank Lampard.
"It's a big disappointment to come all this way and not to win."
"We knew it would be a tough game and we knew what they would bring," added Lampard after making his first start since returning from injury.
"Now we have to go back and win a run of games to keep ourselves in the (Premier) league (fight) and push on in every competition. We have to."
European sides had won the last five Club World Cups, with Chelsea's interim manager Rafael Benitez winning it with Inter Milan in 2010 and a runner-up with Liverpool in 2005.
The Spaniard, an unpopular appointment among Chelsea fans after the sacking of Roberto Di Matteo last month, could face a hostile return after the team's failure in Japan.