Manchester United should be worried by Chelsea's return to form after Bolton thrashing, says John Terry

Chelsea went into Monday night's game against Bolton 10 points behind league leaders United and with people questioning whether Ancelotti's ageing squad had the stomach for the fight.

Goals from Didier Drogba, Florent Malouda, Nicolas Anelka and Ramires, however, have silenced the doubters for the time being and Terry is convinced the likes of United, Arsenal, Manchester City and Tottenham should be afraid.

He said: "Should United be worried about us? I think so.

"In the past we have never given up. United are playing well and getting the right results, getting a bit of luck as well - maybe that will turn."

Victory at Bolton was Chelsea's first away win in seven games. If Sir Alex Ferguson’s men win at Blackpool tonight, the leaders will be 10 points ahead again with 15 games remaining. At the very least, Ancelotti’s side know they have to win their duels with United at home on March 1 and away on May 7.

Terry said: "We've still got to play them twice and if we can win both games then we're right back in it."

If Monday night’s four finishes were all good, then what also impressed about Chelsea was that they never let up. The accelerator remained not just pressed to the floor, but almost through it.

Terry said: "It's been a while since we were this convincing away from home. Everything went really well for us.

"Didier got us off to a great start with probably the goal of the season so far.

"The manager has worked all week on our pressing which we did really well all over the park.

"The biggest celebration was for the fourth goal because the lads were just delighted for Ramires.

"It's his first goal for the club and a good finish. He has settled in well and although he is still struggling with the language, he's a good lad who works really hard."

Chelsea will feel more bullish about closing the gap on United with Drogba in his present mood.

A season scarred by contracting malaria seemed to be passing the Ivorian by until yesterday evening.

His 35-yard goal did not give the impression of a man low in confidence. And Ancelotti was delighted to see it fly past Jussi Jaaskelainen.

"Finally Didier Drogba played a fantastic match," said Ancelotti. "It was a fantastic goal.

"His power and personality are very important for this team. It is crucial that he came back fit and dangerous."