Gus Poyet's first Wear-Tyne derby resulted in a 2-1 win courtesy of an early goal from Fletcher and a late strike from on-loan forward Fabio Borini.
"That was the best feeling I've had here personally," the Chronicle quotes Fletcher as saying. "The dressing room was bouncing afterwards. The music was on and it's been a while since that was the case.
"We knew we had to get in their faces straight from the start and we did that. We got an early goal and I was absolutely delighted with it. It was a great feeling."
Fletcher moved to the Stadium of Light from Wolverhampton Wanderers for a reported £12m fee 14 months ago.