Tottenham's Champions League hopes received a huge shot in the arm after Spus staged a stunning comeback that left Manchester City on the brink of relinquishing its Premier League crown.
Former Arsenal man Samir Nasri looked as if he was going to inflict another damaging defeat on Andre Villas-Boas' men when he put City ahead in the first half.
Despite the return of Gareth Bale, Spurs struggled to get in to the game. Tottenham lacked cohesion and spirit for most of the game but scored three goals in eight minutes to claim a famous victory, which means Manchester United will win the title Monday night if it beats struggling Aston Villa at home.
Roberto Mancini will find the trip back up to Lancashire difficult given that his team dominated the majority of the game. The way in which City folded at the end of the second half demonstrated why it does not deserve to be retain the title.
Mancini admitted the Red Devils are deserving champions, even if he does not believe they have the better team.
"(The title race) was finished three or four weeks ago," Mancini said. "They are not a better team but they deserve to win this title because we lost a lot of points in games we probably didn't deserve to lose. But United won a lot of games in a row with goals and deserve to win the title."
Villas-Boas, on the other hand, can reflect on a much-needed win which puts his team back in the hunt for Champions League qualification. The Portuguese must take huge credit for today's win. His second-half substitutions, and a change to 4-3-3 in the final stages, proved to be the catalyst for the victory.
"I think it was very important for the team to come back," he said. "In the first half we couldn't play our game the way we wanted the set back of suffering a goal so early affected our confidence."
Tottenham remains in fifth place, but its match in hand gives it a big advantage over bitter rival Arsenal, which plays United next Sunday while Tottenham faces lowly Wigan.
Bale has no doubt about the importance of finishing in the top four.
"It's massive," he said. "The club's moving forward every year and all of us players want to be in the Champions League playing against the best week-in, week-out.
"We showed today that we're going to keep pushing to the end of the season to get in the top four."
With Bale back in the ranks, the Spurs faithful seemed optimistic about their chances of pulling off a much-needed victory.
The early signs were good. Amid a vibrant atmosphere in north London, the Welshman jinked past two defenders and fired a swirling shot that Joe Hart needed two attempts to gather.
The atmosphere soon turned sour, though, when City opened the scoring. With just over four minutes on the clock, Carlos Tevez stretched the Spurs back four and picked out James Milner, who fed Nasri and he slotted home with a cushioned volley.
A period of scrappy play followed. Kyle Walker needed treatment after a rash challenge from Nasri while Jan Vertonghen needed a change of shirt after being caught by Edin Dzeko's flying arm in an aerial challenge.
Spurs started to come in to the game more but still lacked the quality to test Hart.The England stopper was only called in to action once in the first period, saving well from Kyle Walker after he collected Dempsey's reverse pass.
Dawson and Vertonghen threw themselves in to the path of Nasri to force the Frenchman to shoot wide.
Hugo Lloris then had to be at his best to deny Dzeko and Tevez in quick succession, but Spurs then went up the other end and thought they should have had a penalty when Michael Dawson's header struck Gareth Barry's arm, but referee Lee Mason waved play on.
Dempsey had a golden opportunity to equalize just before the break but he headed over from Gylfi Sigurdsson's corner.
Yaya Toure stung Lloris' palms with a rasping drive and it took a brilliant tackle from Vertonghen to stop Tevez from racing clear.
Tottenham's push for an equalizer looked destined for failure until the 75th minute. City backed off Bale and he whipped a low teasing cross which Dempsey converted from close range.
The goal lifted Tottenham's spirits and its players threw everything at City. The tactic paid off when Defoe, who had been on the pitch for just seven minutes, latched on to Holtby's through ball and curled a brilliant shot past Hart.
"It was nice," Defoe said. "As a forward, you always want to score goals. I've always said the most important thing is to get three points, but to get three points and get on the scoresheet, I'm delighted."
A carnival atmosphere broke out inside White Hart Lane and the roof nearly came off moments later when Bale killed the game off by lifting the ball over Hart after a brilliant through ball from Huddlestone.
Aleksander Kolarov curled a free kick over, but City knew its chance of taking anything from the game had gone and it was Spurs rejoicing at the final whistle.