Jose Mourinho is thanking his back four for the form that has seen Chelsea open up a 7 point lead at the top of the Premier League.

Chelsea have kept a clean sheet in 7 of the last 10 games, with yesterday’s 4-0 win over Tottenham the most recent in a series of solid defensive displays.

A settled back four of Gary Cahill and John terry in the centre, flanked by Branislav Ivanovic on the right and Cesar Azpilicueta on the left, has pleased Mourinho and the Chelsea manager spoke of his satisfaction with the balance found with that combination.

"We work, we prepare matches, we analyse opponents. You try to find the best balance," Mourinho told Sky Sports.

"Defensively you try to make a shape, you try to find a balance. I like Ivanovic playing right-back more than as a central defender.

"I like a lot the stability of Cahill and the understanding of Cahill with John.

"And I think at this moment Azpilicueta is unbeatable. For many, many matches I haven't seen one player beat Azpilicueta in an individual duel.

"The team is compact, we have a good balance, we are playing well defensively.

"We were all calm. No mistakes, no defensive mistakes. They had control of the ball and of the game but they didn't scare us. That's a good feeling.

"We were very mature. You have to cope with what the game has to give you and sometimes the game gives you a fantastic game, sometimes the game gives you a difficult game and we coped very well with a difficult first half.

"When you are not on the top of your game, but you feel they are not very dangerous, keep calm and you wait for your moment."