Thomas Tuchel's half-time intervention allowed Chelsea to show their Premier League title challenging credentials with an impressive 3-0 win at Tottenham.
After being second best in the first half, Tuchel introduced N'Golo Kante and switched formation and it paid immediate dividends as Thiago Silva and the Frenchman both scored in the opening 12 minutes of the second half, with Antonio Rudiger adding a late third.
It extended their unbeaten start to the season and this statement victory – their third successive win at Spurs' new home – shows they will be contenders to win the title this season.
Tottenham – like Chelsea – were mourning the death of Jimmy Greaves and they are a million miles away from the side that Greaves was a rampant scorer in during the 1960s and even further away from the one that reached the Champions League final just over two years ago.
After winning their opening three games under new boss Nuno Espirito Santo, things are beginning to unravel with a second successive 3-0 defeat in the league.
There are serious concerns over the form of Harry Kane, who was desperate to leave the club this summer and on this evidence it is easy to see why.
With the death of Greaves announced early on Sunday, this was a perfect fixture considering he played for both teams.
The atmosphere was heightened by a warming pre-match tribute to Greaves, where a host of former players came pitchside to join in the minute's applause for Tottenham's record goalscorer, who scored 266 goals in 379 appearances.
Tottenham fed off the energy of that and started the game brightly, with two loose balls in the area just evading Giovani Lo Celso.
Chelsea were a threat on the counter-attack, though, and had Spurs on the rack as they broke in a three-on-two situation.
Mason Mount fed Romelu Lukaku, whose return ball was under-hit, allowing Emerson Royal to get across and block Mount's shot.
With Kane, Son Heung-min, Lo Celso, Tanguy Ndombele and Dele Alli in the team there was a different feel about Spurs from the one that limped to a 3-0 defeat at Crystal Palace last week and they had two big openings.
Son, returning from an injury, sent Sergio Reguilon through on goal and the Spaniard had the opportunity to drive in on goal, but instead he tried to pass to Lo Celso and the ball was cut out.
Then, just after the half-hour it was Son who was in after a Lo Celso pass, but the South Korean's touch was heavy and Kepa Arrizabalaga came out to block the shot.
Tuchel was not happy with what he saw and brought Kante on at half-time and switched to a 3-5-2 formation.
And it transformed the game as Chelsea took a 49th-minute lead.
Marcos Alonso had a flying shot tipped over by Hugo Lloris and at a second corner from that save, Silva climbed highest and found the bottom corner with his header.
Chelsea were rampant and deserved the luck they got for their second goal just before the hour.
Lo Celso ran into trouble and was dispossessed, with Kante afforded space to line up a shot, which took a wicked deflection off Eric Dier and flew into the bottom corner.
Spurs – seemingly shattered from their first-half exertions – had nothing in the way of a response, with Kane's fizzed shot at Arrizabalaga their only meaningful effort of the second half.
At the other end Chelsea had enough chances to rack up a handsome victory, but Lloris saved well from Silva, Timo Werner was twice denied when through on goal and Lukaku headed straight at the Frenchman.
Eventually the third goal came in injury time as Rudiger swept home Werner's cross as Chelsea end the weekend on top of the Premier League table.
