Samir Nasri had given the away side the advantage early in the first half, but three late goals from Spurs produced a stunning turnaround that keeps their top-four hopes alive
The away side took a fifth-minute lead through Samir Nasri, converting James Milner’s low cross, and enjoyed superiority over Spurs for much of the opening hour of the match.
Despite appearing to be in control, however, City allowed Dempsey to tap home Bale's cross with fifteen minutes remaining, before Defoe and Bale scored in quick succession to give Tottenham a vital win in the race for the top four.
Andre Villas-Boas made two changes from the side that earned a 2-2 draw against Basel as Benoit Assou-Ekotto and, more importantly, Gareth Bale returned to the first team at the expense of Kyle Naughton and Lewis Holtby.
Roberto Mancini, meanwhile, rotated his side heavily, making five changes from the team that beat Wigan 1-0 on Wednesday with Edin Dzeko notably replacing Sergio Aguero, while David Silva picked up a knock in training that ruled him out.
After a fairly frantic start, it took just five minutes for the first goal to come. Excellent work from Carlos Tevez allowed Milner to cross for Nasri, who turned the ball home adeptly on the volley to give the away side the lead.
The goalscorer was at the centre of the controversy just minutes later, though, when he went in high on Kyle Walker; despite calls for a red card, referee Lee Mason deemed the challenge unworthy of even a foul.
Kyle Walker then spurned what eventually transpired to be Tottenham's only real chance of the half, firing straight at the onrushing Joe Hart after being played through on goal by Clint Dempsey.
Following that missed opportunity, City quickly took the initiative and almost doubled their lead before the break. Nasri and Dzeko both went close after being put through by the lively Tevez, but the former poked his effort just wide and the latter struck straight at Hugo Lloris in the Spurs goal.
It took Tottenham a little while to get going in the second half, but, aided by several shrewd substitutions from Villas-Boas, began piling on the pressure after the hour mark.
It was, typically, Bale who created the breakthrough goal, receiving the ball on the right wing and flicking a delicious ball to the back post with the outside of his left foot where Dempsey was on hand to convert.
Tottenham's momentum continued and it was mere minutes before the home side completed their comeback with another goal, courtesy of substitute Defoe. After the striker received the ball on the left from Holtby, he ran at Vincent Kompany, cutting inside before lashing an unstoppable effort past Hart into the far corner.
The home side's impetus appeared unstoppable as they extended their lead a few minutes later. Sub Tom Huddlestone embarked on a penetrative run before playing in Bale, who, through on goal, delightfully dinked over Hart to put Spurs 3-1 up and guaranteeing all three points.