With the dust still settling on 19-year-old Nick Kyrgios's fourth-round demolition of world No.1 Rafael Nadal, Dimitrov caused the second seismic shock on Centre Court in the space of 24 hours by outclassing Murray 6-1 7-6(4) 6-2.
The Briton's shattering defeat means that two of the so-called Big Four in men's tennis have departed in quick succession from the grasscourt grand slam, both walloped by members of a brash new generation of big hitters with no fear and scant regard for reputations.
"Everyone's starting to get better," a downbeat Murray said. "The younger guys are now obviously becoming more mature and improving all the time."
It's one thing surrendering your crown, but to suffer such a remorseless beating on your own turf in front of Prince William and his wife, the Duchess of Cambridge, was especially galling.
Yet Murray said: "It's not the toughest loss of my career; that was losing in the final here in 2012 (against Roger Federer).
"I've had a good run here at Wimbledon over the past few years. Obviously it's disappointing for it to end like that."
Novak Djokovic, the man Murray beat a year ago to end Britain's 77-year wait for a men's Wimbledon champion, nearly went the same way before restoring order by digging himself out of a hole to beat dangerous Croatian Marin Cilic 6-1 3-6 6-7(4) 6-2 6-2 and set up a clash with Dimitrov.
UNWELCOME DISTRACTION
The top seed, who was playing on Court One, admitted that the unfolding drama in Murray's match was an unwelcome distraction.
"(There was) so much noise coming from the Centre Court," the Serb said.
The Murray contest was one everyone at Wimbledon wanted to watch, Djokovic said, adding: "I said to the chair umpire, 'Let's just stop the match, put it live on the big screen and let's watch it till they're done. It's going to be better for all of us'."
Seven-time champion Roger Federer may be 32 but will be eager to prove that he can still teach the young guns a thing or two after he advanced to his ninth Wimbledon semifinal with a 3-6 7-6(5) 6-4 6-4 victory over fellow Swiss Stanislas Wawrinka.
He will face 23-year-old Canadian Milos Raonic, who ended the remarkable run of 144th-ranked wildcard Kyrgios 6-7(4) 6-2 6-4 7-6(4).
The Australian's efforts in saving nine match points to subdue Richard Gasquet and then slay Nadal finally caught up with the teenager as Ranoic blasted down his 39th ace to become the first Canadian man to reach the last four here since Robert Powell in 1908.
With cracks beginning to show in the top echelons of the men's game, Canada's Eugenie Bouchard and Romania's Simona Halep heightened the sense of a changing of the guard in women's tennis as both reached the semi-finals.
Bouchard, 20, beat Germany's Angelique Kerber 6-3 6-4 while Romanian third seed Halep, 22, continued her fantastic year to overcome last year's runner-up Sabine Lisicki 6-4 6-0.
They will face-off on Thursday, when both will become the first women from their respective countries to play in a Wimbledon semi-final.
Of the last four standing in the women's draw, only 2011 Wimbledon champion Petra Kvitova has tasted grand slam glory. She now faces fellow Czech Lucie Safarova.
DISBELIEF
A growing sense of disbelief settled over Centre Court and outside on the sun-baked hill, where thousands had assembled to watch on the huge screen, as Murray's imperious charge towards a second consecutive title came off the rails.
Murray had looked impeccable in reaching the quarter-finals without dropping a set but found himself a set down and in deep trouble after only 25 minutes against 23-year-old Dimitrov.
Such was the quality of the 11th seed's tennis that Murray could have been excused for thinking it was Federer in his prime on the other side of the net.
Comparisons with the Swiss maestro appear to have weighed heavily on Dimitrov since he won the junior title here, but with coach Roger Rasheed and girlfriend Maria Sharapova now in his corner, the Bulgarian looks ready to jump the queue of those waiting to get their hands on some major silverware.
"Dimitrov is in a semi-final and he will say, why can't I beat Federer or Djokovic and win the title?" former champion Jimmy Connors, who was commentating for the BBC, said of the player who won the Queen's Club grasscourt title last month.
"He played spectacular tennis today. It won't get easier, so he has to lift his level again. I don't think he is just satisfied with being in the semi-final."
TORRID START
The crowd did their best to lift Murray after his torrid start, but he was clearly having a very bad day at the office. Any hopes for a repeat of his comeback from a two-set deficit at the same stage last year against Fernando Verdasco evaporated in the third set as he was clinically picked apart by Dimitrov.
"As soon as we started warming up I sensed his game was not at the highest level and I was feeling good," said the Bulgarian after ending Olympic champion Murray's 17-match winning streak at the home of lawn tennis. "I held my ground through and the (second set) tiebreak was crucial."
While Dimitrov will contest his first grand slam semi-final, Bouchard will be appearing in her third this year, determined to go at least one better than she did at the Australian and French Opens.
"Yeah, I'm excited to be in the semis," she told reporters. "But never satisfied. I definitely want to go a step further."
