Thomas Tuchel maintained his impressive start as Chelsea manager by getting the better of Jose Mourinho in a 1-0 Premier League win at Tottenham Hotspur on Thursday courtesy of Jorginho's first-half penalty.
German Tuchel, who replaced Frank Lampard last week, has now seen his side take seven points from his three Premier League games in charge with no goals conceded.
Jorginho's 24th-minute penalty, awarded for a clumsy foul on Timo Werner by Eric Dier, did not do justice to Chelsea's domination of a Tottenham side who have now lost three league games in a row for the first time since 2012.
Chelsea had numerous chances to stretch their lead after the break with Callum Hudson-Odoi and Mason Mount going close, although Tottenham striker Carlos Vinicius, playing in place of the injured Harry Kane, headed one glorious late chance wide.
That would have been harsh on Chelsea whose victory lifted them into sixth spot with 36 points from 22 games.
Mourinho's Tottenham, who topped the table in December, have slumped to eighth on 33 points.
It was the first meeting between Mourinho, who won three league titles in two stints at Chelsea, and Tuchel who led Paris St Germain to two French titles before departing in December.
Mourinho said in the build-up that managers could only become great ones by being successful in the Premier League and Tuchel has so far shown he could be a wise appointment.
His Chelsea side were far too slick for a cumbersome home side and the only concern was a failure to score more and losing defender Thiago Silva to a muscle injury before halftime.
"The whole first half we totally controlled the game, very high up the pitch," said Tuchel who became the first Chelsea manager to keep clean sheets in his first three games in charge since Mourinho in 2004.
"A bit more killer instinct and aggression in the box would have been nice but it was a big win in an away game and I am very happy."
For Mourinho it was back-to-back home league defeats for the first time in his illustrious coaching career and the Portuguese could have few complaints.
Chelsea fizzed the ball around on the rain-soaked pitch and almost took the lead in the opening seconds when Werner headed Cesar Azpilicueta's raking long ball just wide.
Tottenham could barely get a kick but Chelsea still needed help to take the lead.
Dier slid in to intercept a long ball and when it broke loose the grounded Spurs defender tried to divert the ball but only succeeded in bringing down Werner.
It was a clear penalty and Jorginho buried the spot-kick past Hugo Lloris.
Hudson-Odoi should have done better than shoot wide early in the second half, Jorginho prodded an effort past the post and Mount forced a great save from Lloris.
Mourinho sent on Erik Lamela and Lucas Moura and finally the hosts looked more menacing with Lamela forcing a low save from Edouard Mendy before Vinicius, with the goal at his mercy, headed Serge Aurier's cross wide.