Middlesbrough 0 Chelsea 1

So while there are clearly plenty of other differences between the two sides, you do not have to look too far to find one of the main reasons why Chelsea sit on the top of the table tonight, with Boro 14 places below them and just a point above the bottom three.

For all their effort and organisation, all their honest endeavour and defensive grit, Aitor Karanka’s side will remain mired in a relegation battle unless they find a way of increasing their attacking threat.

They matched a Chelsea side who have now won six games in a row for long periods of yesterday’s game, and were somewhat unfortunate to concede Costa’s close-range first-half winner. But they only recorded one shot on goal all afternoon, and were wasteful on a number of occasions when an opportunity presented itself on the edge of the penalty area.

They have failed to score in three of their last five matches, and while Adama Traore and Gaston Ramirez attempted to support Alvaro Negredo today, it was far too common to see a dearth of red shirts in the Chelsea box.

Perhaps that was understandable given the strength of the opposition. But while Karanka has proved he is capable of setting up his side to frustrate some of the best teams in the division, he is yet to fully convince when it comes to breaking opponents down, particularly at the Riverside. Twelve games into the campaign, and Boro have still only won twice.

Karanka has spent most of his Boro career wedded to a 4-2-3-1 formation, but having tweaked the system for last month’s game at Arsenal, the Spaniard now appears to have concluded that a three-man central midfield is a better way to go.

On the plus side, it has enabled Boro to contain Arsenal, Manchester City and now Chelsea in recent weeks. On the downside, however, it has done little to make the Teessiders more of an attacking threat.

Antonio Conte’s unusual line-up, with Marcos Alonso and Victor Moses operating as wing-backs, looked much more threatening and fluid, with Moses in particular enjoying a large amount of space as he operated between Fabio da Silva and Ramirez.

Victor Valdes was forced to make a world-class save midway through the first half, tipping Pedro’s goalbound shot over the crossbar after the Spaniard had created space in the box to meet Moses’ pull back, although unlike the first half at the Etihad, it was not really a case of Boro having to defend with their backs to the wall.

As was the case at Manchester City, however, their resistance did not last until half-time. Costa had barely featured prior to breaking the deadlock, but the Spaniard is in the kind of form where he only needs half a chance to make the opposition pay.

His opener was little more than a half-chance, with the ball dropping in his general direction after Alonso’s header from an Eden Hazard corner deflected off Calum Chambers’ back, but Costa’s predatory instincts ensured Boro were made to pay a heavy price for some uncharacteristically hesitant defending.

The home side’s defenders remained motionless, Costa swooped on the loose ball, and with a swish of his left boot, the Chelsea striker had what proved to be the winner.

Boro could claim to be unfortunate to be trailing at the break as they had more than matched their title-chasing opponents in terms of effort and organisation. But whereas Chelsea could boast Hazard and Costa buzzing around the penalty area, ably supported by Pedro, Boro’s chief attacking failing was the lack of penalty-area support for Negredo.

Marten de Roon might have threatened in the sixth minute had Ramirez not slid the ball behind him after he broke down the left, but whereas the Dutchman had powered into the box to great effect during the dying minutes at Manchester City, his attacking forays today were much more limited.

Negredo directed a back-post header wide of the target towards the end of the first half, but that was a rare occasion on which the Chelsea defence were forced to deal with a dangerous delivery into the heart of the box.

Thibaut Courtois did not have to make a save until the 78th minute, although he should have been tested at the start of the second half. Negredo’s dummy enabled Clayton’s through ball to reach the Ramirez, but the Uruguayan curled wastefully over the crossbar from 20 yards.

Boro would have been two down by that stage had Valdes not made another fine save within the opening 20 seconds of the second half, getting down quickly to parry Alonso’s low shot from inside the area, and while Chelsea were only at their fluent best in patches, they should have put the game out of reach in a two-minute spell midway through the second period.

First, the impressive David Luiz won possession and lofted a ball into the area for Costa to cushion back towards Pedro. The Spaniard cracked in an instinctive half-volley, but with Valdes beaten, the ball rebounded off the crossbar.

Moments later, Costa was the provider again, releasing Moses beyond the Boro back four, but while the wing-back should really have scored, he only managed to loft a wasteful shot miles over the crossbar.

A lack of composure was an issue for Boro all game, and Traore’s failure to hit the target with 15 minutes left summed up the home side’s failings in front of goal. N’Golo Kante’s errant square ball teed the winger up on the right of the area, but his dreadful effort never threatened to test Courtois.

Unsurprisingly, Negredo was the one Boro forward to buck the trend for profligate shooting, but when the Spaniard finally found himself with an opportunity to hit the target in the closing stages, Courtois was able to repel him. Negredo swivelled to fire in a sharp low effort following a square ball from Traore, but Chelsea’s goalkeeper got down well to keep the ball out.