Two goals at the start of the second half helped sealed Rafa Benitez's side a place in Sunday's showpiece final against Corinthians.
A well-taken first-half finish from Mata gave the Blues the lead, before a deflected Fernando Torres strike and an own goal from Darvin Chavez promptly after halftime helped see off the challenge of the CONCACAF champion, although Aldo De Nigris did score a superb consolation late on for the Mexican side.
A bright start from the west London side was rewarded in the 17th minute when Mata opened the scoring in style with a sweeping finish after an intricate passing move involving Ashley Cole and Oscar on the left side.
The Blues had come close to taking the lead on three occasions prior to the former Valencia man breaking the deadlock, with David Luiz, Hazard and Branislav Ivanovic all threatening.
Luiz in particular impressed for Chelsea, the Brazil international looking comfortable playing in an unfamiliar midfield role in the absence of Oriol Romeu, after the Masia graduate suffered knee ligament damage against Sunderland on Saturday.
Monterrey grew into the game after going behind, with Jesus Corona's pace and trickery posing Cesar Azpilicueta problems down the left, and but for some wasteful finishing from Aldo De Nigris the Mexican side could well have equalized before the break.
Whatever Benitez said to his side during the interval seemed to do the trick as the club came racing out of the blocks, scoring twice before the second half was five minutes old.
Just seconds after the restart Torres made it 2-0 following a blistering run and pass from Hazard down the left. The striker's shot appeared to be going way off target before it took a considerable deflection and flew into the back of the net.
Chelsea then added a third just moments later courtesy of an own goal from Chavez. The former Atletico Madrid forward was involved once more. His enticing through ball set up Mata, who then looked to pass to Oscar before the intervention of Chavez did the youngster's work for him by diverting the ball past Jonathan Orozco.
The two goals in quick succession had appeared to have knocked the wind out of Monterrey's sails before De Nigris smashed home a consolation goal in added time at the end of the second half to make it 3-1.
Benitez now has a chance to equal Pep Guardiola's achievement by winning a second Club World Cup when Chelsea takes on Corinthians in the final on Dec. 16, after he won the tournament with Inter back in 2010.