The Blues have now won just once in their last six league games but appeared on course to go back to the top of the Barclays Premier League thanks to Didier Drogba's 42nd-minute penalty.

But Everton substitute Jermaine Beckford headed home four minutes from time to hand David Moyes' men a point.

"I am disappointed and angry," said Ancelotti. "Not just because of the result.

"We played good football in the first half and the second half was totally different. We played the long ball. We were a little bit scared. I didn't like this.

"We are working to play a particular kind of football and I don't understand why we have changed it. We have to look at it and I have to understand and change it."

Ancelotti believes that with hard work, however, Chelsea can regain their all-conquering form.

He added: "We have to do better day-by-day on the training ground, in the training sessions. We have to work harder than we are doing. This is the way I know to move on in a difficult moment.

"I am worried yes, because we haven't won a lot of games. The second half was totally wrong. We have to do better.''

Arsenal boss Arsene Wenger is confident Samir Nasri is starting to find his feet in England after his two-goal blast enabled the Gunners to beat Fulham 2-1 and move one-point clear of Manchester United at the summit.

United were not in action with their game at Blackpool called off due to a frozen pitch.

Wenger said: "I always was a strong believer in him.

"Many people questioned me when I took him here but he is showing that he is an exceptional talent and I think there is more to come from him.'

Manchester City manager Roberto Mancini played down an altercation with Carlos Tevez during his side's win over Bolton.

Tevez scored the only goal early on but then launched a verbal tirade at his Italian boss when he was hauled off in the final minute.

But Mancini was quick to play down talk of disharmony.

He said: "I am happy about this. I would like all players to be like Carlos and want to stay on the pitch.

"I needed a player like Mario (Balotelli) on the pitch as he is taller than Carlos. We must continue to score when Carlos doesn't play.''

Tottenham conceded a late equaliser at Birmingham in a 1-1 draw.

Sebastien Bassong put Spurs ahead but Craig Gardner equalised to leave visiting boss Harry Redknapp frustrated.

"We dominated the first half but they brought (Nikola) Zigic on and that's the best I've seen him play," said Redknapp.

"It feels like a missed opportunity. I thought we would win here and at half-time I felt sure we would."

Wigan manager Roberto Martinez praised the Latics for their attitude as they twice fought back from a goal behind to earn a 2-2 draw at home to Stoke.

"I was extremely proud of the second-half performance and the manner we approached the game. You're looking at a very experienced and strong Stoke side and, when you give them the lead, the games become very, very difficult."

Blackburn boss Sam Allardyce was delighted with the way his side responded from last weekend's 7-1 mauling at Manchester United to crush Wolves 3-0.

Allardyce said: "David Dunn's goal settled us down because we weren't looking too clever up to that point. The goal settled us down a bit because of the nerves from last week.

"We were clinical and professional. We're climbing the heights now and I have to credit the players. They were determined to put last week's result behind them and they've done a magnificent job.''