Carlos Bocanegra rocked Chelsea with a late equaliser to leave the champions six points adrift of Manchester United at the top of the Barclays Premiership.

Deadly Didier Drogba looked to have earned Chelsea all three points when he put Jose Mourinho's side ahead in the 61st minute but Bocanegra's 84th-minute equaliser cost the Blues another two home points.

Drogba's strike, his sixth in as many games, made him the first Chelsea player in a decade to score 20 goals in one season.

The Ivory Coast international, who this week admitted he had thought about quitting the club in the summer, momentarily took the focus off Chelsea's defensive problems.

But Mourinho will be hoping influential captain John Terry will recover quickly from his back operation if they are to have any hope of catching Sir Alex Ferguson's men.

Chelsea's current defensive frailties were exposed as early as the 17th minute by Fulham's Moritz Volz - he scored the 15,000th Premiership goal - and demonstrated once more why Terry is such a towering talisman for Mourinho's side.

Chelsea have now conceded eight goals during Terry's absence with a back injury that required surgery in midweek and they looked decidedly rocky without his inspirational leadership.

Midfielder Michael Essien twice went close in the opening three minutes - sending one shot just wide of the target and forcing Antti Niemi into a fine save with his second effort moments later.

In the 13th minute Essien turned provider with a powerful run down the right flank. His cross into the six-yard box fell perfectly for Salomon Kalou but the Chelsea striker just failed to apply the finishing touch.

But they paid for their wastefulness in the 17th minute when Volz put the visitors in front with a goal that would not have pleased Blues coach Jose Mourinho.

Franck Queudrue's throw into the penalty area was dummied superbly by Tomasz Radzinski to leave Volz clear to unleash a right-foot volley into the net.

Volz's strike was the seventh goal Chelsea had conceded since captain Terry had been sidelined.

Fulham should have increased their lead in the 26th minute but an unmarked Wayne Routledge fired over the crossbar from the edge of the penalty area to the dismay of boss Chris Coleman.

But Chelsea equalised in the 35th minute when Liam Rosenior failed to clear a long cross from Makelele and Lampard despatched the loose ball into the corner of the net via the legs of the unfortunate Fulham defender.

Lampard's hopes of claiming his 10th goal of the season were dashed when Chelsea's equaliser was officially credited as an own goal by Fulham defender Rosenior.

Chelsea looked short on confidence with Ferreira proving yet again that he is not a central defender. But with Khalid Boulahrouz suspended, Mourinho had little option but to play the right-back out of position.

He was caught out of position on numerous occasions in the opening half and Fulham were unlucky not to punish Chelsea's poor defending a second time when Brian McBride's header was pushed off the line by Hilario in the 47th minute.

Mourinho, clearly fearing two more dropped home points over the festive period, opted to send on the out-of-sorts Ukrainian striker Andriy Shevchenko in place of full-back Geremi in the 57th minute.

The change worked wonders as Drogba put the home side in front in the 61st minute.

The Ivory coast international headed Lampard's cross home from six yards after Fulham had failed to clear Ashley Cole's long punt into the area. It was his sixth goal in as many games.

But Fulham rocked Chelsea six minutes from time when Essien failed to clear a cross from Queudrue and after McBride's shot was superbly saved by Hilario, Bocanegra pounced to equalise from close range.

Teams:

Chelsea Hilario, Geremi (Shevchenko 57), Ferreira, Carvalho,Ashley Cole, Essien, Ballack, Makelele (Wright-Phillips 86),Lampard, Drogba, Kalou (Bridge 80).

Subs Not Used: Hedman, Morais.

Booked: Ferreira.

Goals: Rosenior 35 og, Drogba 62.

Fulham Niemi, Rosenior, Christanval, Bocanegra, Queudrue,Routledge, Volz, Brown, Radzinski, McBride, John (Boa Morte 68).

Subs Not Used: Batista, Runstrom, Zakuani, Omozusi.

Booked: Queudrue.

Goals: Volz 16, Bocanegra 84.

Att: 41,926

Ref: H Webb (S Yorkshire).