Mourinho's first return to the Blues after his December 2015 sacking ended in a humiliating 4-0 thrashing and United ultimately fared little better in this quarter-final capitulation, secured by N'Golo Kante's stunning strike.
A defensive line-up was expected from United amid pre-match reports of a shortage of strikers, but Marcus Rashford defied illness to start as Mourinho changed his system to match that which Antonio Conte has dominated the Premier League with, and one that the former Blues boss has been far from complimentary about in public.
Mourinho's plans were thrown out of kilter as Ander Herrera picked up two first-half bookings for fouls on the superb Eden Hazard, and Kante - scorer of Chelsea's fourth against United in October - lashed home to give the host the advantage.
Without the inspirational Zlatan Ibrahimovic, a depleted United mustered little by way of response as Chelsea suffocated the game with long spells of possession which flew in the face of Mourinho's pre-match jibes about its perceived counter-attacking style which is set to secure Premier League glory.
Chelsea - which threatened a second late on through substitute Cesc Fabregas - join Manchester City, Arsenal and Tottenham in a star-studded semi-final line-up, but this one-sided victory should serve as a warning of the Blues vast double-winning potential.
The inclusion of Rashford was not Mourinho's only surprise as he fielded a three-man defence in an attempt to stifle Chelsea's electric forward line.
And Hazard jolted the game to life in the 16th minute, spinning away from Chris Smalling on halfway and surging into the box before forcing David de Gea into a plunging save, with the Spain international brought into more reflex work by Gary Cahill from the resulting corner.
Herrera collected his first booking when he bodychecked Hazard and the Belgian remained fundamental when he again breached United's backline, but his aim was well off.
However, Hazard's nimble feet outfoxed Herrera once more 10 minutes from the interval, a late tackle earning a second yellow card from referee Michael Oliver and drawing heated protestations from United, which sent Conte into a guard-dog eyeballing of Mourinho as the Portuguese berated the official from the touchline.
United was aghast as Diego Costa went unpunished for a sly elbow into De Gea's midriff, but it clung on to the break, with Marouane Fellaini helping clog up midfield after replacing Henrikh Mkhitaryan.
There was a yawning gap in United's midfield as Chelsea took the lead, however, Kante drifting off Paul Pogba to rip a brilliant shot across De Gea and into the bottom-left corner.
Rashford was full of endeavour albeit in non-threatening positions until a David Luiz error sent him clear at goal, but he could not beat Thibaut Courtois one-on-one and United breathed a sigh of relief when an unmarked Costa headed wide after Chelsea zipped up the other end and Willian curled off-target.
Pogba dragged a tired shot from 20 yards wide in the sum total of United's attempts at a late equaliser, with Mourinho perhaps now needing to make good on a suggestion he will go all out for Europa League glory after a meek surrendering of the cup.
- Chelsea is now unbeaten in 12 games against Man Utd in all competitions (W7 D5) since a 2-3 home defeat in October 2012.
- Indeed, only twice in its history has Manchester United had a longer winless run against a certain opponent (13 vs Liverpool in 1927 and 13 against Leeds in 1972).
- The Blues' victory means there will be three London teams in the FA Cup semi-finals for the first time since 2002 (Arsenal, Chelsea and Fulham).
- Manchester United had just 26 per cent possession against Chelsea, its lowest figure in a single match this season.
- Chelsea has reached its 22nd FA Cup semi-final, the fifth highest total in the competitions history (Arsenal 29, Man Utd 28, Everton 26, Liverpool 24).