United eventually claimed their biggest win of the season, which allowed them to capitalise on the failure of Chelsea and Manchester City to collect three points, after Paul Scholes broke the deadlock in the second half.
Scholes tapped home after Ali Al Habsi had only been able to parry Nani's low cross into his path.
On his 700th United appearance, it extended a remarkable record.
"That is what we always remember about Paul, the way he ghosts into the penalty box," said Ferguson.
"Obviously as he has got older, he has not been able to do that. He doesn't need to do that now because we prefer him to play central midfield.
"But now he has scored on his 100th, 300th, 400th, 500th and 700th appearance. It is fantastic."
Javier Hernandez atoned for an penalty miss when he added a second before debutants Alexander Buttner and Nick Powell both found the net.
Buttner was slightly fortunate, although he did surge past three players to get in position to let fly with a shot that Al Habsi should have kept out.
There was nothing lucky about Powell's effort though as the 18-year-old belted home from 20 yards.
"Nick Powell is going to be a really good player," said Ferguson.
"He has a great temperament. He has two feet and is quick. He is a great striker of the ball.
"For an 18-year-old boy it has been a terrific day.
"Alexander was a little bit rash at times but he has a great engine.
"He is raw and has a lot of rough edges. Hopefully we can develop that and he will be a really good addition for us."
Ferguson confirmed that Patrice Evra had missed out through injury rather than any form concerns, although Buttner has now applied pressure for the Frenchman's previously certain first-team spot.
"I found out I was playing yesterday [Friday]," Buttner said.
"I wasn't nervous then but when I was standing on the field looking around I was a little bit.
"It was my first goal in my first game and I will never forget it because if I play I want to let it be seen that I can do a good job."