The English side and their interim manager Rafael Benitez will be under pressure to beat Brazil's Corinthians in Sunday's final after becoming the first holders to exit the Champions League at the group stage last week.
"We can't afford to lose the final," Benitez, who won the tournament with Inter Milan in 2010 but lost in the 2005 final with Liverpool, told reporters.
"We will see if Corinthians can play at our level. They have Brazilian quality so we know it will be a difficult match."
Juan Mata finished off a classy move in the 17th minute to give Chelsea the lead, smashing in a left-foot shot after a low ball from Ashley Cole, sent clear by a back-heel from Oscar.
Spain team-mate Torres added Chelsea's second with a deflected drive 20 seconds after the break, his fifth goal in three games.
Mata's cross was turned into his own net by Darvin Chavez moments later to effectively kill off the game, although Aldo de Nigris grabbed a consolation for Monterrey in stoppage time.
"It's nice to be scoring goals again," said a smiling Torres, still hugely popular with Japanese fans despite only recently emerging from an alarming goal drought.
"To hear the fans chanting my name meant a lot to me. Hopefully I can take that form into the final," added the Spaniard, one of the world's deadliest strikers under Benitez at Liverpool.
"This is a massively important tournament for us. We came a long way and it's a trophy we have to win."
Benitez said Torres, on the score sheet for the third successive game for the first time in a Chelsea shirt, was close to his best.
"Fernando is sharper now and has more confidence," said Benitez, who replaced Roberto Di Matteo last month and has yet to win over the Chelsea faithful.
"If we can keep playing at the same level, he will continue to score goals."
European teams have won the last five Club World Cup tournaments. Barcelona lifted the trophy in 2009 and 2011 and Manchester United were the only English winners in 2008.
"European teams are the best in the world," said Monterrey coach Victor Vucetich, understandably frustrated by his side's calamitous start to the second half.
"They pay the most money. Clubs like Chelsea, Manchester United and Barcelona can go out and buy the best players from all over the world. We made mistakes and it cost us dear."
Corinthians, far from convincing in their 1-0 semi-final victory over Egypt's Al-Ahly, won the first Club World Cup in 2000.
