Chelsea boss Jose Mourinho insists the title race is far from over despite United possessing a commanding lead at the top of the Premiership.
The Reds moved nine points clear with a 3-1 win over Manchester City on Saturday, and when Chelsea drew 1-1 with Arsenal - one of two games in hand on United - the gap was reduced to eight points.
But Mourinho, ever bullish about his team's chances, gave a word of warning that the Reds would do well not to be lulled into a false sense of security.
"Ferguson must be happy now because we can say we dropped two points but if he thinks it's over he's in trouble because it's not," he told BBC Sport.
"We are here for the fight and I enjoy the fight. It is better to be in front but let's chase them - we can do it."
Chelsea could reduce the deficit to just two points by the time United take on West Ham at Upton Park on Sunday. The Blues face Newcastle on Wednesday at Stamford Bridge and Everton at Goodison Park hours before the Reds kick off at the Boleyn Ground.
But the fact that the Reds are in a position to test ChelseaÂ’s resolve when under pressure puts the Blues in unprecedented territory under Mourinho. How they cope remains to be seen.
Title Rivals ComparedUnitedWon: 14
Drawn: 2
Lost: 1
Scored: 38
Conceded: 9
ChelseaWon: 11
Drawn: 3
Lost: 2
Scored: 26
Conceded: 9