Barely a week after sacking coach Mohamed Fakhir, the Moroccan side stunned the CONCACAF champions 2-1 in extra time to earn a semi-final meeting with Ronaldinho's Atletico Mineiro on Wednesday.
A double bill at the Agadir stadium also saw what could be the final curtain call for Mohamed Aboutrika, one of the greatest African players of his generation, after he limped out of Al Ahli's 2-0 defeat to Guangzhou Evergrande at halftime.
Thousands of Raja fans filled the town in the hours before their team's match, much to the bemusement of European tourists who had come for a quiet escape from the northern winter.
Afterwards, many of the fans celebrated by driving around in their cars, hooting horns and sitting out of the windows waving flags, creating a cacophony of noise and causing gridlock in the town centre.
The green and white army of Raja supporters also created a fervent atmosphere inside the newly built stadium, singing non-stop for the full game.
Their side went ahead in the 25th minute when Monterrey goalkeeper Jonathan Orozco fumbled a cross from the right and Chermseddine Chtibi slipped home the rebound.
The Mexican side, taking part for the third time in a row, levelled in the 53rd minute when Humberto Suazo floated over a free kick from the right and captain Jose Maria Basanta headed in at the far post.
But Raja stole the game when Ivorian midfielder Kouko Guehi powered home a header from a corner five minutes into extra-time, leaving Monterrey to contemplate another Mexican failure at the competition.
Mexican sides have taken part in each of the last eight tournaments, falling at the quarter-finals four times and reaching the semi-finals on the other four.
Aboutrika's unhappy afternoon began when he missed a gilt-edged chance to give the African champions an early lead, heading over from close range with the goal at his mercy.
Asian champions Guangzhou, under the leadership of Italian World Cup winning coach Marcello Lippi, took full advantage to earn a glamour tie against all-conquering Bayern Munich in Agadir on Tuesday.
"If we played Bayern 100 times, they would win 99 of those meetings but we might win the other one," said Lippi. "That has always been my philosophy."
Second-half goals from Brazilian forward Elkeson and Argentina playmaker Dario Conca ended the hopes of their Egyptian opponents, who were clearly affected by the lack of domestic football which has been suspended in their country due to the political situation.
Aboutrika has already said he would retire after the tournament, although the club have been trying to persuade him to stay on.
"Nothing has been officially conveyed to us," said Al Ahli coach Mohamed Youssef. "We still need Aboutrika, he is of great value, he is a heavyweight player."