Salomon Kalou scored twice as a below-par Chelsea beat Middlesbrough and moved up to second in the table. Kalou volleyed in his first on the hour after David Wheater had failed to clear a Frank Lampard corner. His second came from the same source, with Lampard's corner finding the Ivorian unmarked in the box to head in. Middlesbrough offered little at the opposite end and they have now gone 11 games without a win and remain in the bottom three. Boro manager Gareth Southgate had admitted before the game that plotting Middlesbrough's escape from relegation trouble had cost him plenty of sleep. It is unlikely that this result will enable him to sleep any sounder tonight but he can take some solace from how well his side held an expensively-assembled Chelsea side at arm's length. Luis Felipe Scolari's night may be equally restless as he ponders how to get his side firing on all cylinders. In a round of fixtures in which Manchester United ominously rediscovered their ruthless touch, Chelsea were largely toothless. Middlesbrough started with only new signing Marlon King up front and stuck firmly to the well-drilled tactic of maintaining 10 men behind the ball, allowing Chelsea possession in unthreatening areas, but closing them down quickly at the first sign of danger. It made for a disjointed opening with the rare glimpses of Chelsea pace and penetration finding its match in Middlesbrough endeavour and tackling, both fair and foul. The closest either side came to threatening in the entire half was a 14th minute Michael Ballack free-kick that Boro keeper Ross Turnbull could only parry off his right arm and fortunately away from the prowling home attack. Didier Drogba replaced Florent Malouda at half-time and was presented with an opening almost immediately, the ball ricocheting into his path and giving him a relatively clear run on goal. His shot, which was closer to the corner flag than goal, spoke volumes on the high-profile issue of his continued absence from the starting line-up. Chelsea should have scored in the 54th minute when a Lampard corner was firstly headed on by Ballack and then by Alex to Kalou who inexplicably put his own header over from inside the 6 yard box. Minutes later they did when Lampard again delivered a corner that centre-back Wheater could only weakly head to Kalou 12 yards out and this time the Ivorian was far more clinical with a powerful volleyed finish. The goal dictated a necessary alteration of Middlesbrough's tactical approach which Southgate signalled by bringing on both Tuncay Sanli and Afonso Alves with King and Mohamed Shawky making way but the changes made little difference. With ten minutes to go Chelsea wrapped up the points when Lampard's corner found Kalou completely unmarked in the middle of the penalty area and the striker was able to pick his spot with a powerful header. It was not a vintage display from Chelsea but it keeps their title dream very much alive. Chelsea assistant coach Ray Wilkins: "It is a massive game on Sunday (against Liverpool). Over the past couple of years, we've had some fantastic games with them. "I'm sure this will be the same. I've got no comment to make on whether Liverpool are cracking up. They won't be. "They've got top class footballers. We just worry about ourselves. We go there with a very positive attitude, as we do every match." Middlesbrough manager Gareth Southgate: "We realised we had to keep things tight. You can't open up against a team like Chelsea. "You expect a moment of real class, to be carved open a few times, but that didn't really happen. Our discipline was really good. "We're not where we'd like to be. We've had a tough run. But I don't think anyone in the country expected us to get anything tonight. "We should have had a bonus point. But we know what we have to do. We have stability. We have players who can get us out of the situation we're in. We have to tighten up on the things that went wrong tonight." Chelsea: Cech, Bosingwa, Alex, Terry, Ashley Cole, Mikel, Kalou (Deco 82), Ballack, Lampard, Malouda (Drogba 46), Anelka (Stoch 88). Subs Not Used: Hilario, Ivanovic, Ferreira, Mancienne. Goals: Kalou 58, 81. Middlesbrough: Turnbull, McMahon, Wheater, Riggott, Pogatetz, Adam Johnson, O'Neil, Shawky (Sanli 64), Bates, Downing, King (Alves 64). Subs Not Used: Jones, Taylor, Emnes, Huth, Arca. Booked: Shawky, Riggott. Att: 40,280 Ref: Lee Probert (Wiltshire). Source: BBC