But it was evident from the laboured performance by Carlo Ancelotti’s side that the title nerves are beginning to take hold.

The Blues had to wait until the 43rd minute to break down a stubborn Bolton side who almost snatched a draw in the closing stages.

Manchester United boss Alex Ferguson insists the title is Chelsea’s to throw away and, judging by the anxiety on show at Stamford Bridge, the run-in promises to be a thrilling affair.

There was little evidence that Chelsea would struggle to overcome Owen Coyle’s side when left-back Yury Zhirkov created a chance for the home side in the fifth minute.

The Russian pulled the ball back for Ivory Coast striker Didier Drogba who sent his curling shot over the crossbar.

Bolton’s defence was almost caught out again moments later but Drogba was given offside as he tried to beat Jussi Jaaskelainen.

In the seventh minute, Chelsea had a scare when captain John Terry required lengthy treatment on his ankle following a collision with Matthew Taylor. But the England defender was able to continue without any ill effects.

The Blues had lost their early impetus, though, and Bolton caused problems for the home side when Petr Cech failed to collect a cross from Chung-yong Lee.

Taylor almost profited from Cech’s hesitation but the Czech Republic international quickly regained control of the ball before the Bolton midfielder could strike.

Zhirkov was in the wars in the 18th minute when he went down following a collision with Bolton striker Kevin Davies. The left-back required a hefty bandage on his head to stem the flow of blood before being allowed to continue.

Chelsea almost went in front in the 25th minute when Jaaskelainen punched Drogba’s free-kick straight at Salomon Kalou. But, luckily for Bolton, it bounced off his head and wide.

The hosts were becoming more and more frustrated by Bolton’s battling rearguard and that increased in the 37th minute when Drogba sent another free-kick wide of the target from 20 yards.

Zhirkov was asked to leave the pitch in the 39th minute by referee Lee Probert because he was still losing blood from his head wound.

It was clear the Russian defender’s injury required stitches and Chelsea continued with 10 men – Frank Lampard taking over Zhirkov’s position until he re-appeared in the 41st minute.

The breakthrough came in the 43rd minute when Drogba’s cross was headed home from inside the six-yard box by Anelka.

It was the France international’s first goal in 14 games for the Blues in a barren spell lasting just over two months.

Moments later Kalou tried to increase Chelsea’s lead but his 20-yard shot was well wide of the target.

Chelsea’s opening goal failed to liven up their performance as the second half began.

Bolton enjoyed much of the possession and the home side looked decidedly subdued.

Chelsea had even resorted to lumping high balls in the general direction of Drogba but it was a fruitless tactic.

Kalou wasted a great chance to put the game beyond Bolton in the 54th minute when Drogba put his Ivory Coast team-mate through on goal.

Kalou only had Jaaskelainen to beat but his shot was saved by the Bolton goalkeeper.

But it was a rare chance for the home side, who then survived a penalty appeal when Terry appeared to use his arm to divert a cross from Lee into Cech’s hands.

Zhirkov forced Jaaskelainen into another fine save when he collected a return ball from Lampard and thumped a volley straight at the Bolton keeper.

Anelka was replaced by Florent Malouda midway through the second half.

A superb 40-yard pass from Alex in the 75th minute allowed Kalou to get free of the Bolton defence yet again but his angled drive was well saved by Jaaskelainen.

Three minutes later Lampard almost sealed victory when his 20-yard drive cannoned back of the inside of the post.

Six minutes from time Bolton substitute Johan Elmander was inches away from equalising when he headed a cross from Taylor just wide.

It was, though, the last nervy moment for the hosts, who hung on to move a step closer to achieving the league and FA Cup double.