Tim Krul was the hero by saving two penalties as Norwich beat Tottenham in a shootout after a 1-1 draw to reach the FA Cup quarter-finals for the first time in 28 years.
Norwich were on the back foot in the penalty shootout when Kenny McLean's first kick was saved by Michel Vorm, but Erik Lamela hit the crossbar for Spurs with Troy Parrott and Gedson Fernandes seeing their efforts pushed away by Krul.
The Dutch goalkeeper, who took his time to set himself before each kick, sprinted to the opposite end of the ground to celebrate with the 9,000 joyous travelling supporters in the away end.
At the same time Spurs defender Eric Dier was involved in a confrontation in the stands after being "insulted" by a fan.
Tottenham had actually taken the lead early on through Jan Vertonghen, as the Belgium defender rose highest to powerfully head in from Giovani lo Celso's superb cross.
But they were forced back by Norwich as the visitors caused plenty of problems - Emiliano Buendia and Lukas Rupp both forcing stand-in goalkeeper Vorm into making sharp saves.
Having looked like being left frustrated, the Canaries got a deserved equaliser on 78 minutes as Josip Drmic bundled in from close range after Vorm spilled Kenny McLean's drive.
At the other end, the hosts could have won it with five minutes of normal time remaining but Serge Aurier saw his low shot cleared off the line by the retreating Ben Godfrey. With no further goals in extra time, Norwich made it a night to remember.
Daniel Farke's side will host the winner of Thursday's tie between Derby and Manchester United in the quarter-finals.
Spurs' shock sacking of popular boss Mauricio Pochettino in November paved the way for the appointment of former Chelsea, Manchester United and Real Madrid boss Mourinho as his replacement with the remit of taking the club to the next level by delivering a trophy.
Tottenham's trophy cabinet has been left intact for the past 12 years, their most recent silverware the 2008 League Cup, while you would have to go back to 1991 when they last won this competition.
It looks like they may well go another season without any success as this was their most realistic hope of claiming a cup and they need to overturn a 1-0 first-leg loss to RB Leipzig in the Champions League.
Mourinho sides are traditionally renowned for being strong defensively but they failed to hold on to their lead and have now kept just two clean sheets in 13 matches under the Portuguese manager at Tottenham Hotspur Stadium.
Teenager midfielder Oliver Skipp kept the ball ticking in the middle of the park by completing 91% of his 65 passes, while Lo Celso beside him also impressed, highlighting why Spurs paid £27m to sign the Argentine on a permanent deal.
With time ebbing away, Lo Celso could have won it for Spurs but saw his low drive at the near post kept out by Krul and Fernandes blazed over from a promising position.
Without the availability of skipper Harry Kane and Son Heung-min, Spurs lack bite in attack and they failed to find a winner even after the introduction of teenage striker Troy Parrott in extra time.
Tottenham manager Jose Mourinho: "I think we don't deserve the result but that's football. As you can expect it was a difficult game, as I could expect some of my players were really, really in trouble and they made an incredible effort to try.
"Harry Winks was completely dead. I think he's started 11 to 12 games in a row, we had many, many players in trouble.
"I don't have one single negative feeling towards my players, the opposite, they tried fantastic things. I am really, really sad for the boys, I can cope with the bad result and with negative moments, I've had so many, but I am really sad for the players.
"In this moment I have to think about what's next and I have to speak to my club because I think some of these boys to have a chance to fight Tuesday for a Champions League position they just can't play on Saturday. Particularly in forward positions, behind we've got options but not going forward."
Norwich manager Daniel Farke: "I'm pretty delighted. It was a great performance. Soft skills were great - great spirit and unity - so I'm happy to send the fans home happy. Fantastic support for us and we will take this into next week.
"When you want to beat a top-class side like Tottenham you have to put in an all-round performance. You have to be disciplined, work on a gameplan, maybe allow them to have the ball and be prepared to defend. It is about being brave, being mentally strong. So I have many compliments for my players.
"We have such unity and spirit in this club. We are the biggest underdogs. I can't guarantee if we will stay in the league or win the FA Cup, but we have created memories."
