London - Premier League leaders Chelsea's wobbly form continued as they were held to a dramatic 3-3 draw by Everton here on Saturday.
A see-saw game at Stamford Bridge saw the lead change hands with bewildering regularity, with Chelsea overturning Petr Cech's early own-goal to forge ahead through the inspired Didier Drogba and Nicolas Anelka only to leak an equaliser in first-half stoppage time to Aiyegbeni Yakubu.
Drogba restored Chelsea's lead just after the interval before Louis Saha pilfered a bizarre equaliser to take the tally of goals conceded by Chelsea in their last four games to 10 - a far cry from earlier in the season when their back four was close to invincible.
But this result followed Chelsea's 2-1 defeat by Manchester City last weekend and gave hope to the chasing pack.
Everton, hardly a form team themselves, sensed the prevailing mood with their manager David Moyes deciding to field two strikers in a bid to put Chelsea's creaky defence under pressure.
It worked a treat.
Jo had already seen a curling 20-yard shot saved by Cech when, to the amazement of their travelling fans, Everton went ahead in the 12th minute.
Leighton Baines's inswinging free-kick was met by a combination of Saha and John Terry, and the ball bounced ominously towards the post.
Cech leapt to his left to save but was helpless as it struck the upright, rebounded off his back and nestled in the bottom corner.
Chelsea manager Carlo Ancelotti looked singularly unimpressed but, while his defence might not be as rock-solid as it once was, at least his attack is still as formidable as ever.
Sure enough, within 10 minutes, Chelsea had turned a deficit into an advantage.
Both goals owed much to Saha's defensive sloppiness. First, the French striker was dispossessed by Ricardo Carvalho, who laid off to Frank Lampard on the edge of the area.
The midfielder rolled the ball into Drogba's path and the Ivorian curled a lovely shot into the top corner.
Then, in the 23rd minute, Saha's dismal attempt to clear his lines allowed Branislav Ivanovic to set up Anelka, who belted an inch-perfect shot high into the net.
The natural order restored, that should have been the cue for Chelsea to seize control. Instead, their old deficiencies resurfaced in first-half stoppage time when another set-piece caused havoc.
Baines stabbed towards goal, the ball striking the stricken Carvalho and into the path of Yakubu, who had only been on the field a matter of seconds as a substitute. The Nigerian's finish was routine.
Chelsea, apparently affronted at the concession, stepped on the accelerator just after the interval and were rewarded in the 59th minute when Drogba met Ivanovic's chipped cross with a magnificent first-time volley that flew past Tim Howard.
That, surely, was that. But no: Chelsea's lead lasted just four minutes as another free-kick caused panic in their area.
John Heitinga's chipped cross was met by Drogba, but his header cannoned off the back of Saha's skull and over Cech, who had ventured off his line.
There were late scares for Everton, with Drogba and Michael Ballack both coming close, but ultimately Chelsea's defenders did not deserve to be on the winning side.