John O'Shea credited Martin O'Neill with instilling the belief into Sunderland that they were capable of springing a surprise against Manchester City.
The Black Cats found themselves with their backs to the wall for long periods against the Premier League leaders on Sunday, but pulled off the ultimate smash-and-grab to snatch the points.
With City pressing for a late winner, Sunderland sprung clear on the counter and Dong-Won Ji rounded Joe Hart and rolled the ball into an empty net to send the Stadium of Light into rapture.
O'Shea formed part of a resolute defensive unit that was able to repel everything City threw at it, and the former Manchester United defender was understandably delighted to have seen all of that hard work pay off at the final whistle.
"It's a huge result," he told Sky Sports.
"We saw some of the results coming in yesterday and you're thinking is it good for you, is it bad for you? But the manager spoke at half-time and said we don't want to lose this game 1-0 and people say we did okay and kept them quiet.
"The two chances, great finish from Ji, but (Stephane) Sessegnon as well before that, that was an unbelievable chance as well.
"To be fair to City, they are a great team and had a lot of chances too, but, as a unit, we were great today and credit has to go to the manager for giving us that belief that we weren't going to lose this game. The lads were fantastic."
Sunderland skipper Lee Cattermole led from the front throughout, picking up the man of the match award, and he too was quick to salute the team spirit displayed by the Black Cats as they claimed a notable scalp.
"From start to finish we knew that we had to be together as a team, match all the runners and do all the hard work. But I think that when we had the ball we played as well," he said.
"It was a tough game but it showed a bit of character in the end to come through.
"You have got to be organised as a team, but you have to have that belief as well. We have got that feeling at the minute where we are going into games and believing we are going to win.
"I think we had a lot of bad luck at the start of the season, we were playing the same as we are now but things weren't quite happening. Now it's changing."