Chelsea boss Carlo Ancelotti hailed Frank Lampard as one of the world's best midfielders after his double in the 3-0 victory over Birmingham.
Florent Malouda opened the scoring in the fifth minute but Lampard sealed a fine win with two goals to put Chelsea one point ahead of Manchester United at the top of the Premier League with a game in hand.
Ancelotti said: "We use all the pitch to attack and so Frank is able to run into the box to score. I think he's the best running midfielder in the world. He has this fantastic quality to time his run into the box.
"It's good we are back at the top. We have one more point with a game in hand on United and two points more than Arsenal.
"That's important because on Sunday United play Arsenal. Maybe we can improve our position on Saturday."
Chelsea have coped superbly without their African Nations Cup quartet in January and, in particular, Ivorian strikers Didier Drogba and Salomon Kalou.
They will be back for the trip to Burnley on Saturday and Ancelotti thanked his squad for the work they had done without the pair.
"We did very well in January," added the Italian. "I want to thank my players who did a fantastic job without the African players.
"We could have had some problems without the African players, but we did very well. They did a fantastic January.
"I think we need to have Drogba because he's a fantastic player and, with him, we can play the same football.
"Our philosophy and aims won't change - to play good football and win. We won't change. We'll maintain the same system.
"I'm happy Drogba will be here with us tomorrow morning. He had a fantastic start to the season and will be very important for us in the future."
Ancelotti also revealed that Ghana midfielder Michael Essien, who returned home from the African Nations Cup with a knee injury, could be back inside a month.
Birmingham manager Alex McLeish saw his team's 15-game unbeaten run come to an abrupt end and admitted they had paid the penalty for a poor start.
But McLeish believes his side have the character to bounce back from the setback.
"We shot ourselves in the foot with a bad start," said McLeish.
"It was most unlike us. We were caught flat-footed and that first goal was too easy. We're playing against a world-class side there.
"I don't think anyone has won here this season and they have battered better teams than us.
"We had chances at 2-0 and it would have been interesting had we got the goal back, but we never took the opportunities.
"I'm not disappointed with the players at all. They deserve tremendous credit for the run they have been on and they have the character to bounce back.
"Chelsea are a good side. They have the foreign flavour, the keep-ball and movement is excellent.
"They are one of the favourites for the Champions League, let alone the Premier League. We have kept the ball better than that and were wasteful in possession, but I'll forgive the players this one. There's no disgrace losing here."
The City boss was also hoping to land a couple of new strikers before the end of this month's transfer window.
"I've given the board a couple of names, and I'm hoping they will get something done for us," added McLeish.
"The strikers need help. Kevin Phillips has a small injury and we need to add something to help the others because we'll burn them out playing these guys every week of the season.
"I'm fearful they will lose a little edge if we do, so an extra striker would spice things up a wee bit."
