Manchester United manager Alex Ferguson said that the prospect of ending Chelsea's record unbeaten home run would spur his side on when the two powerhouses of English football meet on Sunday.
"They have got a good home record and everyone knows that has been the foundation of their success for the last four years," Ferguson told reporters.
"I think it's 84 games they haven't lost at home so it's a great challenge for us. A lot of people don't expect us to win which is unusual for our club so there's the challenge."
United go to Stamford Bridge, where Chelsea are unbeaten in a league game since February 2004, on the back of a rare Premier League defeat by Liverpool last Saturday, which put the champions six points behind early season leaders Chelsea.
Ferguson said his side, which will be boosted by the return to fitness of recent signing Dimitar Berbatov in attack, can ill afford another below-par performance against one of their title rivals.
"When you play the big ones you want to get a good haul (of points) out of them. Last season we did very well against the top four. This season we have lost the first one already so we can't afford to lose another one," he said.
Ferguson said he believed Luiz Felipe Scolari's purchase of Portugal midfielder Deco had changed the way Chelsea have played since Scolari replaced Avram Grant as manager following United's Champions League final win over the London club.
He may be tempted to bring fit-again Portuguese Cristiano Ronaldo into his starting lineup following an impressive Champions League performance in mid-week, in an effort to stop Chelsea opening up a big advantage at the top of the table.
"He's a natural athlete. He has trained very well and I would have no qualms about playing him on Sunday. I have to decide whether it's the right time but I have no fears at all. He is pestering to play," said Ferguson.
United will be without the suspended Nemanja Vidic, while Michael Carrick is injured and goalkeeper Ben Foster has been ruled out for up to eight weeks with ankle ligament damage sustained in a reserve team game yesterday night.