Chelsea boss Andre Villas-Boas admits they need to work hard to dislodge Tottenham as London's top dogs.
The tag has long belonged to Chelsea before this season.
"They've overtaken us in the Premier League table this season, for sure," he said.
"Both clubs have fantastic history, but there is no comparison between the clubs over the last 10 years."
Villas-Boas felt Spurs' ascent could work in favour of the chasing pack, with them, Manchester City and Manchester United all knowing a slip-up might cost them dearly.
"Anything can happen. Eight points (to Spurs) is still a distance you can turn around.
"We have a job to do to prove the doubters wrong. We have to do that on the pitch, not with words."He said: "The fact there are three teams so close together, it means a couple can lose points bearing in mind recent happenings - City losing three in four, and United trying to find that consistency like us.