Roman Pavlyuchenko came off the bench to hit the two goals that sealed our fifth place Premier League finish and send visitors Birmingham into the Championship.
The Russian striker replaced Peter Crouch just before the break and gave us the lead with an excellent curling effort shortly after half-time.
But the visitors threw themselves a survival lifeline when Craig Gardner hammered a strike home from the edge of the box 10 minutes from time.
However, we desperate to end our season on a high, and Pavlyuchenko’s second, his 14th of the campaign, deep into injury time gave us a dramatic late win and sealed Birmingham’s fate.
Liverpool could have overtaken us by bettering our result at Aston Villa, but they were defeated anyway, and it means a first outing in the Europa League for the Club next season.
Injuries to Rafael van der Vaart and Steven Pienaar meant that Harry Redknapp was forced into two changes from our win at Anfield last Sunday.
In came Jermain Defoe up front with Crouch, while Tom Huddlestone made his return from injury in the centre of midfield alongside Sandro, with Luka Modric moving out to the left.
It was a game with so much riding on it – and perhaps the nerves were showing in the scrappy early stages.
Ben Foster was forced into two saves by Sandro, one from a tight angle after good link-up play with Crouch, the other a curling effort from the edge of the box.
Danny Rose was again looking good at left-back, and his fantastic ball across the face of the Birmingham goal on 23 minutes deserved someone getting on the end of it.
So we were well on top going into the break, shortly before which Crouch was replaced by Pavlyuchenko after a clash of heads.
Younes Kaboul and Modric had forced further saves out of Foster before the interval, but the visiting stopper could do nothing about the Russian’s first real sighting at goal four minutes into the second half.
Roger Johnson had failed to intercept Rose’s pass, and when the ball fell to Pavlyuchenko 20 yards out, he showed little hesitation before curling home a stunning strike into the far corner.
It could have got worse for Birmingham moments later when a break down the left resulted in Defoe getting a shot away, blocked by the head of the excellent Curtis Davies, before Modric’s deflected shot was kept out by Foster.
Although the visitors were well aware of the fate that awaited them were they unable to find an equaliser, they rarely threatened.
Johnson had their best chance around the hour mark, but he failed to direct his header goalwards from Sebastian Larsson’s corner.
Meanwhile, we continued to press with Huddlestone and Pavlyuchenko both going close as 15 minutes remained – the Premier League table standing with Birmingham in the bottom three.
Another five minutes ticked away and it looked like their worst nightmare was becoming a reality, before an absolute God-send.
A corner was cleared to Gardner on the edge of the box, and he may never hit a sweeter strike in his career, sending a low drive crashing into Carlo Cudicini’s bottom corner.
It sent the visiting support into an understandable frenzy as it was enough to take their team out of the dreaded drop zone – at least for the time being.
Gardner nearly doubled his tally soon after with a free-kick that skimmed the roof of our net, while we realised our duties to other teams down the bottom and pushed for a winner at the other end.
Niko Kranjcar replaced Huddlestone in an attacking switch, while Sandro’s acrobatic ball across goal was only inches from the head of Defoe.
Into the last five minutes and Birmingham were safe by the skin of their teeth when more bad news hit their fans – despite heading to a home defeat at the hands of Blackburn, Wolves had scored a vital second goal to lift them out of the bottom three on goal difference.
To rub salt into their wounds, Pavlyuchenko’s deflected shot in stoppage time crashed in off the bar to give us the victory we so wanted, and it meant no way back for Birmingham.
And so, a memorable 2010-11 campaign ended on a fitting high note, while credit must go to our fans for showing respect for the distraught visiting support with a standing ovation after the final whistle.
Spurs (4-4-2): Cudicini; Kaboul, Dawson, King, Rose; Lennon, Huddlestone (Kranjcar, 84), Sandro, Modric; Crouch (Pavlyuchenko, 41), Defoe
Subs not used: Gomes, Assou-Ekotto, Corluka, Jenas, Palacios
Goals: Pavlyuchenko (49)
Birmingham (4-4-1-1): Foster; Carr, Johnson, Davies, Ridgewell; Larsson (Derbyshire, 75), Gardner, Ferguson, Fahey; Beausejour; Jerome
Subs not used: Doyle, Murphy, Redmond, Mutch, Valles, Asante
Goals: Gardner (79)
Referee: Mark Clattenburg