Offside goal by Costa puts Norwich in the drop zone

It has been a chastening period for a group of players who had conceded 19 goals in their past seven games and, until the improved display in the 1-0 ­defeat by Leicester City on ­Saturday, had ­appeared destined for relegation.

The result at the King Power ­Stadium may not have provided any points but the level of performance will have given Neil some encouragement.

Chelsea, unbeaten in the league under Guus Hiddink, the club’s interim ­manager, made four changes to the side that beat Southampton on ­Saturday.

It was one of those men brought in who ensured that Chelsea made the perfect start to proceedings.

Kenedy, the left back, required less than a minute to make an impact as ­Chelsea ripped through the Norwich defence with startling ease.

Eden Hazard took up possession just short of halfway before playing the ball wide to Kenedy, who danced inside a couple of challenges before unleashing a fierce effort into the far corner.

It was the start of a frenetic first half in which both teams appeared to give little pause for thought when defending and attacked at every opportunity.

Norwich, seeing plenty of the ball, came close to an equaliser when ­Cameron Jerome headed inches over the crossbar.

Norwich’s response to conceding so early the contest was positive. Jerome, guilty of a glaring miss at Leicester on Saturday, was full of running and ­Wes Hoolahan found space in between the Chelsea defence and midfield.

Kenedy danced inside a couple of challenges before unleashing a fierce effort into the far corner

ADAM DAVY/PA

But it was in the final moments of the first half that Norwich’s world came crashing down as Chelsea doubled their advantage.

A quick throw-in by Cesc Fàbregas allowed Hazard to find Bertrand ­Traoré and it was his through-ball that allowed Costa to run clear and beat Ruddy.

Norwich, still fuming at the officials after they thought that Thibaut ­Courtois had deliberately picked up a backpass, were now incandescent with rage after Costa’s goal was allowed to stand ­despite him being a yard offside.

Fired up by the injustice of Costa’s goal, the home side came out full of energy for the second half and Jerome volleyed wide at the far post after being picked out by Gary O’Neil’s fine cross.

Jerome had managed three goals in 27 appearances before this ­contest and his inability to hit the target came back to haunt Norwich eight minutes after the interval.

A cross to the far post from Hoolahan was headed back across goal by Russell Martin and Jerome, with nobody near him, glanced his volley against the crossbar and over from six yards.

There could be no doubting the effort and enthusiasm of the home side but their inability to convert chances had Neil jumping up and down on the touchline in frustration.

But with 22 minutes remaining, ­Norwich finally found a way through. A delightful through-ball from the ­impressive Hoolahan released Nathan Redmond and his effort flew past the onrushing Courtois.

Norwich continued to move forward and O’Neil curled an effort wide of the far post after a lovely move that ­involved Hoolahan teasing the Chelsea defenders as he had done for much of the evening.

Dieumerci Mbokani, the substitute, gave Norwich more pace and power to their attack as Chelsea began to drop deeper and deeper into their half.

Redmond, enjoying more and more space, fired inches wide of a post as Norwich tried in vain to find an ­equaliser, while Costa missed at the other end when his effort dribbled past the goalmouth.

There was still time for Norwich to press forward with the crowd roaring their side on, but the elusive goal would not come, a feeling that is becoming all too familiar at Carrow Road.

● Marina Granovskaia, Chelsea’s director and lead negotiator, has spoken to Miralem Pjanic’s advisers and established that there is a £31 million buyout clause in the Bosnia-Herzegovina midfielder’s contract at Roma (Matt Hughes writes). Pjanic, 25, is one of the players recommended by Antonio Conte, the Italy coach who is expected to be named the new Chelsea manager this month. The club would have little trouble meeting the buyout clause or Pjanic’s £60,000-a-week salary and it is understood that the player is interested in moving to Stamford Bridge despite the possibility of missing out on Champions League football.