United's lead over Chelsea has been pegged back to three points after the weekend's matches, but Ferguson believes their 2-2 draw at Middlesbrough was a point won rather than lost.
The Barclays Premier League leaders took the lead at the Riverside courtesy of Cristiano Ronaldo's 37th goal of the season - but two goals from Brazilian striker Afonso Alves put Boro ahead.
It was left to Wayne Rooney's late deflected effort to secure a share of the spoils.
Ferguson said: "We could have lost the game, there's no question. They had some chances - and at times our defending was a bit haphazard, I thought.
"But at other moments we could have won the game, because some of the quality of our football was terrific.
"That point could be important, absolutely. Our goal difference is good obviously, but we cannot take anything for granted," he added.
"The nature of the club is that we never give in, and that's a great quality to have at this time of year.
"It sends out a signal to everyone that we will never give in. We will stretch ourselves in every game as long as we can."
