On a night when Chelsea were never at their best at St James' Park, Didier Drogba underlined his importance to the champions after coming off the bench to score the only against a Newcastle side that will feel unfortunate to no longer be Carling Cup contenders.

The powerful Ivorian had only been on the field six minutes, in the 79th, when he scored with a fine free-kick that not only encapsulated all that has been impressive about his performances this season, but also sent his side into the competition's semi-finals.

Prior to his introduction and Chelsea had very much flattered to deceive but when his goal arrived it had all the earmarks of true quality. After Arjen Robben had won a free-kick on the right corner of Newcastle's box, fellow substitute Michael Ballack rolled into the path of his team-mate and with a curling effort the ball was bent beyond Shay Given, who got a touch but was unable to save his crestfallen team-mates.

With Newcastle's treatment room having resembled an episode of ER in recent weeks, the return of Scott Parker will have delighted Glenn Roeder, who must have been considering the option of dusting off his own boots.

In contrast, Chelsea's bench housed the likes of Frank Lampard, Ashley Cole, Ballack and Drogba and yet, the team put out by Jose Mourinho was still able to boss the early stages, as the home side struggled to find any real rhythm.

Chances were, though, conspicuous by absence as Chelsea in particular were wasteful in the final third, with Andrei Shevchenko again a nervous and lethargic imitation of his former self - before being substituted in the second half.

With the game descending into a lull, midway through, Obafemi Martins woke everyone present when after taking down Nolberto Solano's clever pass with a fine first touch he proceeded to unleash a thunderous 25-yard shot that gave Henrique Hilario not a prayer but the ball crashed against the crossbar and bounced down on, but not beyond, the line.

From the resulting corner Hilario was hilarious, as Nicky Butt's on target but slow moving volley was parried to safety by the most unnecessary of two-fisted punches.

With those in black and white buoyed and showing a genuine relish for the battle on a cold North East night, Parker fired in low at Hilario, who saved comfortably at his near post. As the half drew to its close Chelsea were restricted to long range efforts as Michael Essien and John Obi Mikel both had drives that are possibly still travelling.

Shevchenko may have struggled to live up to his reputation but his time in England has not been characterised by good fortune and again, in the last action of the half, astute work was not rewarded when after taking Essien's pass into his path he drove across Given only for the ball to strike the far post and rebound to safety.

At the interval Mourinho had seen enough and sent on Lampard, who needed just ten minutes to register his side's first shot on target but Given was equal to an archetypal drive from the edge of the box.

On the hour mark Hilario showed that whilst he may be unorthodox he is also brave, as he raced off his line to smother at the feet of Kieran Dyer after the fit-again midfielder had sprung on to Emre's charmingly disguised through ball.

Ballack was the next superstar to be summoned as the entirely ineffective John Obi Mikel was replaced but still Chelsea failed to impose themselves on a Newcastle side well marshalled by Nicky Butt, Parker and Emre in the middle of the field.

They have, though, a real match-winner in Drogba and just as he did against Everton he found another sublime effort that once again got Chelsea off the hook.

In injury time Lampard went close to adding his name to the scoresheet with a spectacular effort of his own, when after intercepting Given's misplaced pass he lofted the ball over the Irishman but the post came to his rescue. Newcastle may have impressed but it is Chelsea that progress; as is so often the case with Mourinho's men.