Chelsea recorded an important victory at home to a defensively set Middlesbrough thanks to two second-half Salomon Kalou goals.

The Ivorian took advantage of two poor pieces of Boro play inside their own box to seal the win, which had looked in some doubt for the first hour thanks to the visitors' dogged defensive display.

The first was a volley after substitute Didier Drogba had hassled in the area, and the second a result of goalkeeper Ross Turnbull's missed interception, both from Frank Lampard corners.

The win sent us back above Liverpool and Aston Villa into second place behind Manchester United in the Barclays Premier League.

Luiz Felipe Scolari was able to call on John Terry who returned to the Blues' defence after back trouble to captain the side, alongside Alex who kept his place for a 50th start due to Ricardo Carvalho's recurring hamstring injury. John Mikel Obi was back in the line-up after suspension against Ipswich with Juliano Belletti making way, absent from the 18 through illness.

Middlesbrough manager Gareth Southgate handed a debut to Marlon King alone in attack, while Emanuel Pogatetz returned at left-back following suspension.

It was the visitors who kicked off in chilly, wet conditions but it was the Blues who quickly took the initiative. First Lampard was able to measure up a free-kick from a similar range to the one he scored on Saturday, and then Kalou jinked his way past a host of Middlesbrough defenders, but both shot and dribble were blocked.

Florent Malouda had enjoyed a busy start to the game, his direct running causing Boro problems, but a late Mohamed Shawky challenge sent him crashing to the ground. The Frenchman looked to be struggling but quickly regained freedom of movement.

It was Malouda's colleague on the left-hand side that should have opened the scoring 13 minutes in. José Bosingwa's deep cross from the right was met by Ashley Cole, who had galloped forward to support the attack. He would have expected to hit the target with his header four yards out, but instead found the side netting.

Where Cole failed to make Ross Turnbull work, Michael Ballack succeeded, curling a low free-kick towards goal two minutes later, but the goalkeeper did the basics well, getting his body behind the ball and diverting it clear.

After this bright start, Chelsea's tempo dropped, allowing Middlesbrough a more comfortable existence as they defended deep, normally King the only man ahead of the ball while the trio of Matthew Bates, Shawky and Gary O' Neil kept things tight in midfield. That, allied with a reluctance to attack through wide areas, was again giving Chelsea problems.

Subsequently it was 20 minutes before another opportunity arrived, Salomon Kalou heading Lampard's corner over the bar, when Alex was better placed behind him to go for goal.

Half-time brought about one change from manager Luiz Felipe Scolari. Drogba was introduced from the bench, in place of Florent Malouda. Kalou moved to the left and Anelka lined up on the right.

It was only seconds before the Ivorian was gifted a chance by an errant Stewart Downing pass. Drogba held off David Wheater but screwed his angled shot wide.

Eight minutes into the second half, Terry sparked a return of some much-needed urgency with a surge up the field. Successive corners were forced and from the second, Chelsea should have been in front. Alex won the initial header and Kalou should have flicked his in, but instead sent it up and over the bar.

Three minutes later Chris Riggott sent Drogba crashing to the ground and was yellow-carded by ref Lee Probert.

This time it was Alex's turn to hit the free-kick but it was deflected wide. From Lampard's corner, Chelsea went in front. Alex challenged, Wheater half-cleared with his head, but it fell to Kalou who volleyed powerfully into the roof of the net from 12 yards.

The relief could be felt all around the Bridge, as now Middlesbrough would have to come out and play if they were to take anything back to the north-east.

That gave Chelsea more space in which to play, and Drogba and Anelka linked up beautifully to carve out another chance. Anelka went through but was forced wide, and couldn't summon the necessary power to beat Turnbull at his near post.

Five minutes later he raced clear again, again down the right and this time squared into the empty box for the oncoming Lampard. He would have fancied his chances with 14 goals already this season, but snatched at his shot and the ball rolled wide.

Kalou could have doubled his tally when he followed up another parried free-kick, this one from Lampard, but will want to quickly forget his slip and air shot that followed it.

All the while, Drogba was showing flashes of his ability with deft touches and tight control, but it remained the England midfielder at the centre of the action. When Bosingwa looked inside, he found the 30-year-old in space and hungry for the ball.

In space and 25 yards out, Lampard's next move was inevitable, but his low shot along the greasy surface was narrowly wide.

With 10 minutes remaining, the three points were sealed with Kalou's second of the evening. Once again it was a Lampard corner that led to the goal. Turnbull came for the inswinging cross, missed it, and the 23-year-old was on hand to nod into an empty net.

The reward for a brace was immediate substitution, Deco had been waiting for a couple of minutes to enter the action, and so Kalou's goal was the perfect way to sign off for the evening.

Another late appearance from the promising Miroslav Stoch brought extended cheer for Blues supporters, who will have gone home at the final whistle well satisfied with an important victory, particularly in the light of Liverpool's draw at Wigan.

Chelsea (4-3-3): Cech; Bosingwa, Alex, Terry (c), A Cole; Ballack, Mikel, Lampard; Kalou (Deco 81), Anelka (Stoch 88), Malouda (Drogba h-t).

Goals: Kalou 57, 80

Middlesbrough (4-4-2): Turnbull; McMahon, Riggott, Wheater, Pogatetz (c); Johnson, O'Neil, Bates, Shawky (Tuncay 63), Downing; King (Alves 63).

Booked: Shawky 9, Riggott 55

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