A debut goal from substitute Samuel Eto'o was scant consolation as Everton suffered defeat against Chelsea in a drama-filled nine-goal battle at Goodison Park.
Two strikes inside the opening three minutes from Diego Costa and Branislav Ivanovic stunned the Blues, who hit back on the stroke of half-time through Kevin Mirallas.
A Seamus Coleman own goal restored the visitors' advantage midway through the second period - and triggered a frantic spell of six goals in the final 23 minutes.
Steven Naismith registered for the third time in as many games to get Everton back in it, but Nemanja Matic responded just five minutes later.
Substitute Eto'o then headed in to give the Toffees another lifeline, but Ramires and Costa finally killed the contest in the dying minutes.
Roberto Martinez made just one enforced change from last weekend's 2-2 draw with Arsenal, as Aiden McGeady came in for the injured Steven Pienaar.
It meant Romelu Lukaku got to pull on an Everton shirt against Chelsea for the first time, the Belgian having been ineligible to face the Stamford Bridge outfit during both games of his loan spell last term.
However, the Blues got off to a nightmare start. Almost from the kick off, Chelsea caught the hosts cold with a flowing move that ended with Cesc Fabregas feeding a ball through to Costa and the Spain international struck his third goal in as many Premier League appearances.
Then, with no more than three minutes on the clock, Ivanovic was played into space behind an advancing Everton rearguard. Arms went up for offside, and replays suggested the Blues had just charged out in time. Yet, the flag of the referee's assistant stayed down, much to the annoyance of goalkeeper Tim Howard, who was left scooping the ball from his net for a second time.
Stunned by Chelsea's early assault, Everton needed to regroup.
They eventually found something akin to their familiar passing rhythm and had the ball in the net on 16 minutes. From a corner, Lukaku's header bounced back off the crossbar, and though Sylvain Distin was well placed to turn in the rebound, the Frenchman was waved offside and denied what would have been a first league goal since May 2011.
Naismith, looking to build on his impressive scoring start to the season, dragged a shot wide at the end of the very next move and, moments later, saw another effort cleared from inside the six-yard box by the outstretched foot of Gary Cahill.
Having sampled Everton's threat, Chelsea retreated further and further back and were made to pay on the stroke of half-time.
Picking up possession in the middle, McGeady spread play out wide to Coleman down the right, and when the full-back centred, Mirallas met the ball brilliantly to head across goal and into Thibaut Courtois' top-right corner.
Seven days earlier, Martinez's men had suffered the pain of relinquishing a two-goal lead to be held to a 2-2 draw by Arsene Wenger's Gunners. Now in position to inflict the same agony upon Chelsea, they started the second half with an obvious air of intent.
However, Lukaku was perhaps too keen to made an impact in blazing a shot high into the Gwladys Street after being teed up on the edge of the box, while, at the other end, Howard had to be quick off his line to expertly thwart Costa after the Brazilian-born forward was again poked through by Fabregas.
Some pushing and shoving between Coleman and Costa got the temperature rising inside Goodison just before the hour-mark, the latter earning a booking for refusing to let the matter drop.
And the Evertonians inside the stadium were on their feet in frustration again when Lukaku, set to burst through on goal, was questionably flagged offside just minutes later.
That was nothing compared to the disappointment of seeing Eden Hazard's shot ricochet off the leg of Coleman and past a helpless Howard on 65 minutes, though Naismith immediately reduced the arrears back to one.
Found as he darted into the box by the marauding McGeady, the Scot's toe-poke past Courtois was ice cool. 3-2.
Back to within a goal, the Toffees were soon guilty of letting the Londoners slip away from their grasp once again. Matic was afforded too much time and space on the edge of the box and the Serbian fired in low via the foot of the post.
Yet, in this rollercoaster encounter, you always felt their were more twists and turns ahead.
Less than six minutes into his debut, Eto'o, on for McGeady, caused the loudest roar of the day.
Loitering around the edge of the box as Leighton Baines stood over a free-kick, the Cameroonian manoeuvred himself into position, planted his feet and accurately guided a header past Courtois from 15 yards. A goal against his former employers. 4-3.
Sadly, the renewed belief that soared around Goodison Park was short-lived. Sixty seconds later, a one-two between Matic and Ramires left the latter bearing down on Howard and the Brazilian steered in Chelsea's fifth.
Another neat passage, this time involving Coleman, Eto'o and Mirallas, so nearly resulted in the Belgian notching the goal of the game, but his airborne flick frustratingly licked the outside of Courtois' post.
With time running out, and Everton chasing a reward for their endeavours, John Obi Mikel's back heel found Costa and the striker slotted in a sixth.
Many of the Blues' players will now head off on international duty. They resume club action at West Bromwich Albion in a fortnight's time.