The Black Cats secured their first victory of the season on Sunday, with Fabio Borini stepping off the bench to seal a dramatic 2-1 success at the Stadium of Light.
Newcastle were undone six minutes from time when Sunderland sprang forward from a free-kick inside their own half and Jozy Altidore teed up Borini to crash home a spectacular winner.
Pardew concedes that the Magpies paid the price for a momentary lapse in concentration, but was left bemused by the decision which put the home side on the front foot.
He told Sky Sports: "I really feel like we've been done by a sucker-punch.
"The referee had a hand in that goal as well, because the linesman gave us a throw-in and I don't think that's a foul. We just switch off and they have capitalised from that.
"The free-kick wasn't a free-kick. Cheick (Tiote) is out of position and Yohan (Cabaye) misses the cut-off of the pass, and then we're open a little bit.
"We only made two or three errors in the second half, I think that's the only shot they've had - or the only chance they've had."
Victory for Sunderland saw them prevail in Gus Poyet's second game in charge, and his first at the Stadium of Light.
Pressed on whether a change in the dugout helped to galvanise the Black Cats, Pardew added: "I think it's obviously going to add a new feeling to the group.
"That type of victory is the sort of victory you want when you come in as a manager. I think he has been very fortunate today to get it."