The Canaries broke the deadlock through Anthony Pilkington in the first half and manager Paul Lambert was furious when his team were denied a blatant penalty when Ledley King clambered over Grant Holt in the Spurs box.
His anger intensified moments later when Jermain Defoe equalised, but the Canaries boss had the last laugh when Elliott Bennett hammered a powerful drive through a sea of defenders to inflict a massive defeat on the home side.
Tottenham, perhaps fatigued after Saturday’s energy-sapping draw at Sunderland, lacked venom in attack with Gareth Bale their only threat going forward, while in defence they were terribly shoddy.
With just one win in their last eight league games, they seem destined to throw away their chance of dining at Europe’s top table and, with the way they are playing at the moment, they may well end up not even qualifying for the Europa League.
Newcastle are level on points with the fourth-placed Londoners and Chelsea would draw level with their neighbours if they beat Fulham tonight.
To say that Spurs were the sole architects of their own downfall today would be wrong, however. Norwich, who became only the third team other than both Manchester sides to win at Spurs this year, were creative, organised and very clinical and Lambert’s stock will rightly rise after this impressive victory.
The writing appeared to be on the wall for Spurs from the start. A mix-up allowed Elliott Bennett to feed Holt but Benoit Assou-Ekotto stole in.
Holt beat King to a Pilkington cross but could only prod wide.
Another defensive lapse allowed the Canaries to take a shock lead with 12 minutes gone.
Younes Kaboul blocked Aaron Wilbraham’s shot and Kyle Walker went to clear, but his attempt ricocheted off King into the path of Pilkington, who calmly stroked the ball past Brad Friedel.
Spurs were rocked by the goal and Norwich continued to play confidently amid a now tense atmosphere.
Friedel tipped Pilkington’s wicked cross just wide and Bradley Johnson fired a free-kick into the wall.
Bale galloped past Russell Martin and sent a low ball across the box that just evaded Defoe’s tap-in.
Then, with half an hour gone, King tangled with Holt in the Norwich box but referee Oliver’s whistle stayed silent.
Lambert was incensed, marching over to fourth official Phil Dowd while cursing at the top of his voice.
Spurs then raced up the other end and equalised. Defoe latched on to a slide-rule pass from Jake Livermore and chipped over John Ruddy. Lambert turned away in disgust and launched a bottle of water into the advertising boards.
Friedel saved from Pilkington in the dying minutes of the first half and Spurs were forced into a substitution when Kaboul hobbled off and was replaced by Ryan Nelsen.
Lambert approached referee Oliver as the teams went down the tunnel at half-time, clearly still angry at being denied a spot-kick.
Emmanuel Adebayor replaced Saha at half-time and Spurs started the second half strongly.
They could have been ahead had Russell Martin not blocked Bale’s powerful shot.
Assou-Ekotto exchanged passes with Adebayor and burst deep into the Norwich box but Ruddy tipped over with an outstanding save.
Holt slipped past King to get on the end of a through-ball and cross for the un-marked Johnson but he blazed well over from eight yards.
Johnson then took his frustration out on Lennon by hacking the winger down as he raced down the flank to picking up a booking.
Lambert fumed at Oliver’s refereeing again on the hour when Adebayor pushed Wilbraham in the Tottenham box but no penalty was given.
Soon after Luka Modric found Bale, who drifted in from the flank and struck a sweet shot that hit the bar and bounced out.
Spurs were then stunned as Norwich took the lead again through Bennett’s first Premier League goal.
Martin ventured forward to lay the ball off to the former Brighton man and he thumped a 20-yard strike beyond Friedel.
Bale flicked an Assou-Ekotto cross just wide as Tottenham seemed destined to fail in their attempt to grab an equaliser.
The 3,000 away fans chanted “Thursday nights, Channel Five”, clearly unimpressed with the hosts’ Champions League credentials.
Wilbraham came off with a nasty cut to his head and his replacement Simeon Jackson missed a sitter with 10 minutes left after some good work in the air by Morison.
Norwich thought they should have had another penalty with two minutes left when Nelsen appeared to handle Steve Morison’s cross but referee Oliver waved away the visitors’ protests.
Spurs threw everything at the Canaries in the five minutes of added time but it was clear they would not find a way through and Norwich took away the three points.