The Dutchman's side were forced to withstand plenty of pressure at the Stadium of Light, but they ultimately made the hosts pay for not taking their chances.
Sunderland had a number of good goalscoring opportunities through striker Jozy Altidore, but the visitors needed only one as Pajtim Kasami headed home from a corner in the second half.
"It was what we needed," he said. "Three points with our schedule is perfect for us.
"At times you would have to say we would have been happy with the draw.
"They pressed us in the first half and we didn't do enough, but in the second half we did better - but I think it's fair to say it was a scrappy win."
"He did well but needs momentum," he added.
"With people coming back from international duty he really stepped up and we came away with a good result."
