Wayne Rooney's double fired United to a 2-0 victory over the 10-man Baggies at Old Trafford on Sunday afternoon to lift them back into pole position after neighbours Manchester City lost at Swansea.
Ferguson was full of praise for his side after they overturned City's advantage but insists their performance was the most important thing following Thursday's Europa League defeat to Athletic Bilbao.
"It's a surprising day for us I suppose," he told Sky Sports.
"I'm happy to be there because only a few weeks ago we were five points, and at one time seven points, behind and now we're a point ahead.
"So we've turned around eight points and it's a credit to the players and also to the resilience of our squad because, as everyone knows, we've had a lot of injuries.
"I don't care about being top of the league just now. More important was our own performance.
"We needed that performance after the disappointment of Thursday. But the players played fantastic football today and I was really, really pleased with that part."
Ferguson reserved special praise for defensive duo Rio Ferdinand and Jonny Evans, adding: "In particular I thought our two centre-backs were absolutely brilliant today.
"Jonny Evans and Rio Ferdinand - fantastic performance by them. I think when you get that solid foundation, you can go into other things in terms of the attacking part, and there's no concerns over what's happening at the back."
It seemed United's afternoon could be tainted when striker Danny Welbeck appeared to pick up a knock and was substituted 13 minutes from time.
But after speaking with the forward, Ferguson does not have any serious concerns.
"He thought he was feeling his hamstring tighten up but then the next minute he said the pain had gone so I think it was just a bit of tightness," he said.
"We just said we'd take him off, take no risks, with 10 minutes to go and hopefully he'll be okay."