The Black Cats ran out winners at Craven Cottage, scoring three times in the process for the first time in nine months, and O'Neill wants his side to take heart from their win.
Second-half goals from Steven Fletcher, Carlos Cuellar and Stephane Sessegnon gave the Black Cats their first win since September and the boss is hoping the new-found momentum can be carried through to next weekend's game against high-flyers West Brom.
"It's very pleasing to get the win away from home - I would have taken the win in any shape or form, but it was a good win and we scored some good goals," he said.
"The players are looking forward to the next couple of games at home. It's always a good atmosphere at the Stadium of Light.
"Winning is a boost of confidence ahead of a very important game next week."