The Red Devils conceded two precious Barclays Premier League points after a goalless draw with Blackburn Rovers at Ewood Park on Sunday.
United, without the injured Wayne Rooney, relied on Dimitar Berbatov in attack but the best two chances of the match fell to Antonio Valencia in the first half.
 Chelsea, who beat Aston Villa 3-0 at Wembley on Saturday to reach the FA Cup final, now lead the table by one point with a match in hand over United.
Ferguson said: "That's a fantastic result for them (Chelsea). They've got a home game against Bolton on Tuesday which they will be expected to win."
DOMINATED POSSESSION
Ferguson rued the missed chances, particularly one by Valencia just before half-time.
He added: "He should have scored. It was a golden chance and at a good time, five mins before half-time.
"We had the chances in the game. We dominated possession but you have to create those chances and take them.
"It's always a difficult place to come to for anyone. We should have done better."
United's next Barclays Premier League fixture sees them travel the short distance to play neighbours Manchester City on Saturday.