LIVERPOOL (AFP) - Chelsea spurned the chance to claim top spot as Steven Naismith's first-half header earned Everton a 1-0 victory on Saturday which condemned Jose Mourinho to his first Premier League defeat since returning to England.
Naismith, celebrating his 27th birthday, struck on the stroke of half-time at Goodison Park as Everton gave new boss Roberto Martinez his first victory in the league since replacing David Moyes.
Everton remain unbeaten and, on this evidence, look capable of continuing the progress they made under Moyes which persuaded Manchester United to make the Scot their new manager.
This was, however, a disappointing setback for Chelsea ahead of the start of their Champions League campaign as Mourinho discovered there remains work to be done if he is to mark his first year back at Stamford Bridge with another title.
There were contrasting debuts for Chelsea's Samuel Eto'o, who joined on a one-year deal from Russian club Anzhi Makhachkala, and Everton's Gareth Barry, signed on a season-long loan from Manchester City.
Eto'o was denied what looked a certain debut goal by Barry's stunning last-ditch tackle in an incident which summed up a contrasting 90 minutes for the duo.
The Cameroon international required just five minutes to get his first sight of goal but his usually-reliable predatory instincts deserted him when he rose unmarked inside the penalty area to meet Ramires' pinpoint delivery only to head wide.
There was further evidence of ring-rustiness on Eto'o's part when he almost cleared the roof with a 25-yard effort and his frustration continued in the 29th minute.
The former Barcelona and Inter Milan player, eight yards out, had the goal at his mercy when Andre Schurrle intercepted Tim Howard's sloppy pass and squared to the forward, only for Barry to come to the rescue with a challenge which swiftly endeared him to the home fans.
It was poor from the USA goalkeeper, yet the error undoubtedly stemmed from a new emphasis on playing out from the back from Martinez.
The home side spurned a golden chance of their own four minutes later when Kevin Mirallas found Naismith in space inside the penalty area only for the Scotland international to fire wide.
Next it was Chelsea's turn to threaten, with Howard redeeming himself for his earlier error by denying Ramires before Schurrle shot woefully over the crossbar from an inviting position and Branislav Ivanovic headed over.
And Chelsea were left to rue those misses in added time when Jelavic, at the back post, nodded Leon Osman's clipped cross back into Naismith's path and, with Petr Cech caught in between, he powered home a header into the roof of the net.
Mourinho's team almost equalised within a minute of the restart when Schurrle got in behind the Everton defence only to find the side netting with his chipped effort.
Oscar and Frank Lampard were introduced just before the hour mark as Mourinho tried to swing the game in Chelsea's favour.
Martinez made changes of his own, with £13 million (S$26.2 million) signing from Wigan James McCarthy introduced.
There were predictable boos for former Liverpool striker Fernando Torres when he was brought on in one final throw of the dice from Mourinho, yet it failed to have the desired impact and Everton, in fact, finished the stronger.
Cech thwarted a viciously struck effort from Mirallas and the home side were incensed when David Luiz escaped with a yellow card for upending the Belgian close to the halfway line as the Toffees countered, with the home side adamant he was the last man.
And their advantage could even have doubled with a minute to go when Leighton Baines struck the crossbar with a dipping free-kick.