The Tykes and Black Cats played out a stalemate on a blustery and wet night at Oakwell.
Reds' chief Stendel was pleased that not only did his side maintain a four-point buffer over their rivals, but that they became the first team to stop them scoring in the league this season.
"It was a close game like we expected it to be," admitted the German, whose side are still second on 74 points - five shy of leaders Luton.
"We had two chances through Mamadou (Thiam) to go in front.
"The wind was very difficult, especially for (goalkeeper) Adam Davies.
"I think a draw for both sides was okay.
"We have a lot of clean sheets and this is down to all players.
"Sunderland played a lot of long balls and were helped by the wind.
"I think we were better than them but in the end neither scored and we keep the gap between us. We're satisfied.
"Most of the time if we score, then we win. But this was not so easy against a good side."
The Reds now face a quick turnaround, as they head to South Yorkshire rivals Doncaster on Friday night.