Strategist Sir Alex Ferguson admits: victory on Sunday against London's team would secure the English champion title for his team.
Currently leading the tournament table, Manchester club is ahead of the capital team by three points, so a win at "Old Trafford" stadium to improve goal difference would lift Chelsea to the first place.
"If we win, most likely we will secure the first place," said the Scot. "We play fantastically at home, probably one of the best in the world according to this indicator. We have to prove it again on Sunday."
Last time 'Red Devils' stumbled in front of their own fans over a year ago. However, a concerning fact could be that in the first clash of these teams in London, Chelsea won 2-1.
"That victory allowed the opponents to recover. Winning the English championship is very difficult, we know it well because we have been fighting for the first place for almost 19 years," added the specialist. "On Sunday the team will be fresh, as some players rested in the Champions League. It is very important at this stage of the season."