The Red Devils moved five points clear of nearest challengers Liverpool on Wednesday night with a 3-0 victory over Fulham at Old Trafford.
Ferguson's men are eight clear of surprise package Aston Villa in third with Chelsea 10 behind and Arsenal a distant 15 adrift with 13 games of the season remaining.
The Scot claimed before the triumph over the Cottagers that he now saw the Premier League title battle as a two-horse race, with Rafa Benitez's men their only realistic rivals.
He was a little more circumspect after seeing his side tighten their grip on top spot, but believes United now have the strength in depth to hold off the competition.
Eleven years ago, Ferguson saw his side relinquish a 12-point advantage over eventual winners Arsenal as injuries bit hard in the closing stages.
ChangesThe riches at the Premier League and European champions' disposal was demonstrated against Fulham with in-form Ryan Giggs unable to even secure a place on the bench.
And Ferguson said: "You can never be dead sure but it is fair to say Chelsea have an uphill fight now.
"Things can happen. We were 12 points clear of Arsenal in 1998 but we got a lot of injuries and lost the league.
"Now we can cope with it, like we have done in the last few weeks.
"That is the change at this club. We have such a big squad we can make changes."