Steve Davies latched onto a Toby Alderweireld clearance before cooly slamming the ball beyond Michel Vorm.
Dale's dramatic last-minute equaliser secured them a trip to Wembley which was thoroughly deserved.
Both of Dale's goals came from poor defensive work from Tottenham, perhaps a sense of arrogance shown by the Premier League side?
In particular, Ian Henderson's first-half opener came from Harry Winks holding onto the ball for too long in the middle of the pitch.
The majority of the Spurs side were deep in the Rochdale half when Harrison McGahey turned over play with a crunching challenge on Winks.
This set the Dale away on the counter-attack as Andrew Cannon received the ball and put it on a plate for Ian Henderson who made no mistake with the finish.
We could go on to pull apart the poor defensive work from Spurs. However, that would be taking away the credit that Rochdale deserve.
From the off, Rochdale showed a tenacity and determination to not allow Spurs play their passing style of football.
Tottenham dominated the second-half but Keith Hill's side showed a never-say-die attitude even when they went behind in the 89th-minute.
To show the determination until the very last second is a testament to Hill and his struggling side. Up against the odds with seconds to go and they managed to grab a memorable draw against a Premier League heavyweight.
Lucas Moura shining on debut
New signing Lucas Moura made his full starting debut after featuring for the final minutes against Juventus in the Champions League.
Not many of the Tottenham players could come out of the draw against Rochdale saying they performed to their usual standard.
However, Moura was certainly Tottenham's brightest spark, proving a constant offensive threat as he grabbed his first goal for Spurs just before the hour mark.
The Brazilian was played into Dale's box by Moussa Sissoko where he coolly put it beyond a helpless Josh Lillis with his weak foot.
In comparison to the 'going rate' of a player of Lucas' quality, £23m seems a bargain and the winger definitely made a great impression on his full debut.
Pochettino puts draw in perspective
Following the unexpected draw, boss Pochettino addressed the media and insisted the result was nothing to worry about.
He said: "Sure we will compete again to try to go through."
It seemed after such a good run of results against some of the biggest clubs in England and the European giants in Juventus, an away trip to Rochdale would be a stroll in the park.
For obvious reasons Spurs, Pochettino and co. would have wanted a victory at Spotland but in the grand scheme of things, the draw was not disastrous.
It proved not to be for Spurs but they should look to take the positives out of the game, at the end of the day they are still in the cup.