Michael Essien says that Chelsea will travel to Manchester United for Sunday's Premier League championship decider "up for it" and full of confidence, having gone from strength to strength in recent weeks as they have breathed fresh life into the defence of their title.

The Ghana midfielder admitted his own confidence and that of his team-mates had suffered so badly during the club's mid-season slump that he laboured over making a simple pass. But, for reasons that he cannot fully explain, something "suddenly clicked" and the team have been able to piece together the run of form that has put the destiny of the title back in their own hands.

They trailed United by 15 points on 28 February, albeit having played a game fewer, but they beat them at Stamford Bridge on 1 March and they have now taken 25 points from a possible 27. If they were to win at Old Trafford, as they did decisively last season, they would go above United on goal difference at the top of the table, with only two matches to play.

Chelsea's final games are against Newcastle United (home) and Everton (away) while United must play two relegation-threatened teams, Blackburn Rovers (away) and Blackpool (home).

"We have to beat Manchester United at Old Trafford this weekend to ensure we are in the driving seat and I can assure you we are up for it," Essien said. "The team is playing well and I have no doubt we will give it everything we have to beat Man United."

Essien described his own season as "sweet and sour" and he reflected on the period when it "just wasn't coming off" for his team. "I was asked by friends many times what I felt the problem was and I couldn't explain," he said. "All I can say is when you hit a bad patch, you think about everything too much. The simplest pass becomes a difficult task because you spend time thinking rather than just letting things flow.

"When you are on form, you receive a pass and just let it go but when you are down you think too much and lose possession. I am glad to say after many weeks working hard on the training pitch it suddenly clicked and now we are in with a chance. Maybe it's a confidence thing – who knows?"