Tottenham manager Jose Mourinho took the unusual step of praising an ex-Chelsea boss for spearheading the Blues' victory over his side on Sunday.
Mourinho tasted home defeat for the first time since taking over the Spurs job as one of his former employers triumphed 2-0.
Willian scored both the visitors' goals in the opening 45 minutes, while Tottenham's comeback efforts were hamstrung by Heung-Min Son's red card late on.
Defeat leaves Spurs six points adrift of their London rivals, who currently occupy the final Champions League qualifying place.
And Mourinho was full of praise for the tactical set-up in the Chelsea camp - although inspiration apparently came from an unexpected source.
"They were better than us in the first half. It is not difficult for me to admit it. They played in a system they are very comfortable with. A system they played for two years with Antonio Conte. Lots of their players are very comfortable with it. Alonso, Azpilicueta, Kante, Willian, players very comfortable in this system," Mourinho told reporters after the game.
"They created problems for us in the first half, not problems of clear scoring situations but like you say, with the control they had. The game was basically in our half despite them not creating a lot. But in the end you are right and it’s easy for me to admit they were superior.
"But you look to the goals and they are not a consequence of any superiority.
"The first goal is a short corner with a big mistake. We know how to defend short corners, we train how to deal with short corners. The players involved in the short corner solution were not focused. So you concede a goal with a short corner and you concede a goal with a penalty. So the goals didn't come from that superiority, they came from mistakes.
"Then in the second half we changed, we felt we needed to change and we had much more control and we were in our best period of the game and one goal would change the emotion of the game because the game on the pitch was already changed.
"In the first half [the ball] was in our half and in the first 15-20 minutes of the second half we were much more in their half, the game changed.
"We were looking for a goal and instead of a goal comes a red card. Then the game obviously is easy for them to control with players technically good and one player more. Then it was more difficult."