Chelsea captain John Terry has fired a warning to rivals Manchester United.
Terry's side struggled to beat Newcastle on Wednesday and trail United by five points after 17 league games.
But the England skipper said: "They are probably playing the best football they can play at the moment. They've had very few injuries so far.
"Whereas we know as a team we've got another level to go to. We need to take the game to teams and then no-one can live with us."
Terry's team overcame a dogged Newcastle side thanks to a second-half match-winner from substitute Didier Drogba.
And he added: "We must go on a run of games and keep winning.
"We must keep the pressure up. Christmas is a difficult period. United have got tough games. We must just keep winning and keep on like we know we're capable of."
"Drogba was injured. A normal player, with a normal attitude would not have played"
Chelsea struggled to break down Glenn Roeder's makeshift side until Drogba, a half-time replacement for the injured Ricardo Carvalho, slid the ball home after Andriy Shevchenko had miscued his shot.
Drogba, nursing a hamstring injury, started on the bench along with Andriy Shevchenko.
But unlike Drogba, the Ukrainian striker had been dropped by manager Jose Mourinho.
Mourinho added: "I make decisions from my analysis. I took him out of the team because I felt the team needed different qualities.
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"I think (Shevchenko) took it as a professional. He was not happy but behaved properly. He came on when I decided and did well for the team."
Mourinho left Drogba in the dugout until half-time because of his injury problem. He added: "Drogba was injured. A normal player, with a normal attitude would not have played.
"So I was trying to explain to him the best decision was to save him. If the result was positive at half-time we would not have played him.
"But I felt we needed him at half-time. His attitude in the game and the way he worked for the team meant he was very important for us. He is one of the top players at the moment."