Mauricio Pochettino's men are Leicester's nearest challengers at the top of the table.
With eight games to go, Spurs have established themselves as the biggest threat to Leicester City's chances of pulling off one of the greatest achievements in recent memory. And Dembele conceded that not even among their own squad did they believe that they would be in contention so late in the campaign.
"Yes, [we're] surprised," he told the London Evening Standard.
"We believe in ourselves but we surprised everyone and of course we are very happy about this."
While both Arsenal and Manchester City have a game in hand over the top two, the fact that Spurs and the Foxes both won their most recent fixtures means that the chasing pair have an enormous amount of work to do if they hope to remain in the mix, and would arguably mean that one more slip up would confirm that it is a two-horse race.
Should the Gunners and City be unable to catch the top two, then whatever happens, Mauricio Pochettino's men have undoubtedly had a wonderful season, considering that they have only flirted with finishing in the top four on a handful of occasions in recent years.
And although the surprise that Dembele has admitted to suggests that they would have been delighted with a second place finish if they had been offered it at the start of the season, now they are well in the running, they will surely be desperate to go one spot higher.