Tottenham were dumped out of the FA Cup by Championship opposition for the second year in a row after Iliman Ndiaye fired Sheffield United to a 1-0 fifth-round win at Bramall Lane.
Exactly one year ago to the day since they were beaten by the same scoreline at Middlesbrough, Spurs again succumbed to a team in the division below them after a limp display in South Yorkshire.
After starting Harry Kane on the bench, they fell behind to Ndiaye's 79th-minute opener and could not find a way back into the game.
Asked if he regretted benching Kane, assistant head coach Cristian Stellini said: "It is not a regret. We need to look at the medium period, we have many games. Harry Kane played in the last six games, one time with a fever, one time with a problem, we have to take care of our best player. It's not about Harry because we played with Richarlison, Lucas Moura and Sonny. I think it is good enough to play in this competition and against this sort of team."
Spurs' trophy drought will now stretch beyond 15 years and they have now exited the premier domestic cup competition at the fifth round stage for the fourth successive year.
With Antonio Conte still out of the country as he recovers from gall bladder surgery, the manager will evade some of the flak for this defeat but, with his future still up in the air, the pressure is mounting on him ahead of a crunch period in the Premier League and Champions League.
It was a glorious night for the Blades, who reached the last eight for the third time in four years and they are now one win away from Wembley, which is supplementing their promotion campaign in the Championship.
This fixture had all the hallmarks of that night on Teesside for Spurs, but they still opted to leave Kane on the bench.
Spurs have been notoriously slow starters this season and were so again in a largely forgettable opening 20 minutes.
Lucas Moura, making his first start since November, wasted a good opening as a stray Sheffield United pass played him in but after driving into the penalty area he dallied and could not find a man.
Spurs' dominance began to grow and Richarlison, starting as a number nine, had a good chance but fired over while Moura saw a mis-hit cross skim off the crossbar.
For all of their control, the Premier League side should have gone in at half-time trailing.
Pierre-Emile Hojbjerg got his header back to goalkeeper Fraser Forster all wrong and Ismaila Coulibaly nipped in but, with Billy Sharp screaming for a square pass, he skewed a shot into the side-netting.
Spurs started the second half with some purpose and Ivan Perisic glanced a corner over while Son Heung-min could not find the target after creating room for himself on the edge of the area.
But they could not keep up their momentum and the hosts began to come into the game more.
Even the introduction of Kane did not help Spurs regain their verve as Pedro Porro curled wide after Hojbjerg's long ball sent him clear.
As the second half wore on, it appeared more obvious how the game would pan out, and duly did so 11 minutes from time.
Some sloppy defending from Sanchez and Porro allowed Ndiaye to wriggle free in the box and he fired a low shot in at the near post, which did not cover Forster in much glory.
Tottenham had to wait until deep into injury time to muster a chance at sending the tie into extra-time but Kane inexplicably headed Perisic's cross over and United saw it through.
Stellini said: "I think we missed a big opportunity and we have to apologise to the fans.
"There were 5,000 of them here to watch our performance and we apologise because we missed a big opportunity."
Man City vs Burnley
Man Utd vs Fulham
Brighton vs Grimsby
Sheffield United vs Blackburn
Sheffield United are back in Championship action when they visit Blackburn on Saturday at 12.30pm, live on Sky Sports Football.
Wolves host Tottenham at Molineux in the Premier League on Saturday at 3pm.
