Scholes was introduced as a substitute on the hour with United trailing 2-1, and he helped inspire a 3-2 turnaround which saw Robin van Persie score three.
Ferguson insisted that Scholes was the catalyst for United's late rally.
He told MUTV: "We didn't start playing until Scholes came onto the pitch with his range of passing.
"His consistency of passing and his presence in midfield turned the game for us."
United play their next Premier League match after the international break at Old Trafford, when they entertain Wigan Athletic on Saturday, September 15.