Everton have recorded their first Premier League win of the Roberto Martinez era thanks to a Steven Naismith goal against Chelsea at Goodison Park.
Samuel Eto'o should have worked Tim Howard when found by Ramires in the fifth minute of the match, but the Cameroon international ballooned a header over the bar having got between Phil Jagielka and Sylvain Distin.
Both teams looked lively going forward, and the Toffees had a chance of their own when Leon Osman won the ball in midfield and laid it off to Ross Barkley, who slipped in Naismith to cross for Nikica Jelavic. However, the Croatian headed tamely into the arms of Petr Cech.
The best chance of the first half came in the 29th minute, and it fell to Eto'o. Howard was guilty of over-elaborate play in his own area, gifting the ball to Andre Schurrle, who squared to the striker.
With the goal at his mercy, Eto'o looked certain to score, but the heroics of Gareth Barry kept his team's clean sheet intact.
The American goalkeeper made up for his earlier error by making a fine stop to deny Ramires from finding the net in the 35th minute.
Roberto Martinez's men were living dangerously at the back as the visitors began to create chances at will.
Hearts were in mouths as Ramires skipped through the defence, tracked only by Leighton Baines. The England international did enough to put the Brazilian off, but the ball broke for Schurrle, who then fired high over the bar.
Branislav Ivanovic should have done better when Juan Mata landed a pinpoint free kick on his head, but once again Chelsea manager Jose Mourinho was left fuming as Howard watched the Serbian's effort over the bar.
The decisive moment of the first period came in stoppage time when Leon Osman found Jelavic at the back post, and his header back across goal left Naismith to nod home from close range.
The West Londoners were unfortunate to be trailing at the break and sought to rectify that in the second half.
Everton were forced onto the back foot, with Schurrle's dink over Howard slipping just past the post seconds after the restart.
Eden Hazard, Eto'o and Ramires all had efforts as Chelsea began to dominate possession, but the home side managed to grab a toe-hold as the half wore on.
Oscar almost made an immediate impact after coming on in the 57th minute, as he went down claiming for a penalty after trying to skip between Distan and Osman.
Replays showed that he had a case for a foul, although contact may have been on the edge of the area. Nevertheless, referee Howard Webb did not blow the whistle and waved away all protests.
Chelsea poured forward in search of an equaliser in the final 15 minutes, which left gaping holes in their defence.
Hazard and Luiz went into the book for cynical fouls on Seamus Coleman and Kevin Mirallas, who both found the visitors short at the back.
Barkley was brought down on the edge of the area by John Obi Mikel late on, and Baines struck the top of the bar with the resulting free kick.
That was the closest anyone came to scoring another goal before the final whistle, meaning that Everton not only avenge their two losses last season, but also inflict the first league defeat of Mourinho's second reign in charge of Chelsea.