Campbell admitted the goal was a blur as he took a superb angled pass from James McClean to finish low under advancing Boro keeper Danny Coyne.
"I just remember running as fast as I could - I couldn't breathe very well!" joked the striker with safc.com as he reviewed his first Sunderland goal since April 2010.
"James played a great ball in for me and I just put it away. I though James did really well today - he had a great game.
"It's a dream start. I didn't expect to get any minutes today so to get on and score was brilliant."