Chelsea 3 Middlesbrough 0:Unless Manchester United implode, silver is the best that Chelsea can expect in the Premiership this season. The true currency of their prospects in the knockouts will emerge over the next three weeks, when they will be seeking a place in the FA Cup quarter-finals, a trophy in the League Cup final and, crucially, progress towards the biggest prize of all in the 24-carat Champions League.

Saturday's initially fitful though ultimately convincing victory over an improving Middlesbrough not only opened up a gap of 10 points between Jose Mourinho's team and third-placed Liverpool but also suggested that Chelsea are reassembling their act in good time for a spring offensive on a variety of fronts.

While Didier Drogba caught the immediate attention with two well-struck free-kicks, the fact that the defence kept a fifth successive clean sheet will have given Mourinho equal satisfaction as he headed back to Portugal for a short break.

Cup football is about efficient, disciplined defending combined with the ability to snap up chances. Of course, this applies to football in general but in sudden-death or even two-leg situations the ability to grab and hold a lead is paramount.

Chelsea's season threatened to fall apart over Christmas when they dropped points at home after failing to stay ahead of Reading and Fulham but now, with Petr Cech back in goal and John Terry restored to the defence, opponents are less likely to be allowed back into matches once they have fallen behind.

Not that Mourinho's luck with unfit players has completely changed for the better. He had hoped that Terry's recovery from back surgery would allow Michael Essien to move back into midfield alongside Frank Lampard and Claude Makelele but on Saturday Ricardo Carvalho pulled out with flu which meant that Essien stayed in the defence.

While this guaranteed Stamford Bridge a juddering confrontation of African lions as Essien met Yakubu Aiyegbeni it again deprived Chelsea of their most consistent presence in midfield and for much of the first half Julio Arca and George Boateng achieved parity for Middlesbrough between the penalty areas. With Andrew Taylor and Stewart Downing regularly turning Chelsea's defence on the left, moreover, the chances of Middlesbrough taking something from the game to add to their victory over the champions on Teesside in August appeared quite bright.

Certainly Chelsea would have endured a less comfortable afternoon had Mark Viduka not headed wide after rising unchallenged to meet Taylor's centre in the 12th minute. And had Middlesbrough moved men forward more quickly to support Aiyegbeni when he beat the offside trap five minutes later, reaching the left-hand byline only to find there was no one to pass to, they might well have taken the lead then.

Chelsea's attack was off target for much of the first half and before this season Drogba might have brooded over shots going high or wide. Such is his present confidence, however, that when Middlesbrough's panicky attempts to clear a long throw from Wayne Bridge in first-half stoppage time gave Chelsea a free-kick, the Premiership's leading scorer drove a low shot through a thicket of legs to beat Mark Schwarzer at the right-hand post.

A centre from Taylor which deceived Cech and hit the crossbar renewed Middlesbrough's hopes but only briefly.

Just past the hour Arjen Robben, another recent casualty, came off the bench and within a minute had gone down, got up and seen an intended square pass across the penalty area take a 90-degree deflection off Abel Xavier to increase his team's lead.

Southgate augmented his attack with Jason Euell, who promptly brought down Robben for Drogba to score again from the free-kick, this time helped by a ricochet off Andrew Davies which took the ball further beyond Schwarzer's reach.

Drogba has now scored 25 in all competitions and Chelsea will trust that the consistency of his marksmanship denies Arsenal the League Cup and sees off Porto in the Champions League, not to mention Norwich or Blackpool in the FA Cup on Saturday.

The champions resume league action in March with Mourinho stressing that they have to "win, win and win" to keep alive their chances of a championship hat-trick. But at the same time Manchester United have to lose, lose and lose and that may be a tall order.

Guardian Service