Chris Coleman heavily criticised his players after the dismal defeat to Sheffield United but they bounced back strongly with a superb win over Nottingham Forest.
And a delighted Coleman was full of praise for his players for the mental toughness they displayed as Aiden McGeady's first half header saw them climb out of the Championship relegation zone.
Mark Warburton's Forest side dominated possession and had 22 attempts at goal compared to Sunderland's one, from which they scored the winner.
Coleman made three changes to the side embarrassed at Bramall Lane with Donald Love, Callum McManaman and Josh Maja handed starts.
And the Black Cats produced a spirited display at the City Ground, holding on for three crucial points that lifted them out of the Championship relegation zone.
Coleman said: "That performance and the mentality was particularly pleasing for us in terms of where we are.
"Our last performance was poor. Today spoke volumes of the players, sleeves rolled up, they were ready for it.
"We have to be in games because we can create something, we have players with a bit of creativity.
"We have to make sure when we do it that it is 1-0, not when we are two or three down.
"It is about being strong as a team and unit and suffering together when it is nil nil and digging in and then we will create something magical, like we did today.
"The overall performance was very pleasing and promising.
"We knew they would be wounded after Boxing Day but I thought we showed really good intentions.
"First 20 minutes we were very good, Forest had their moments as you'd expect but then we got a great goal.
"Second half really we sat back too much and should have continued from the first half when we passed the ball well and caused them problems.
"One nil up, you are trying to hold on to that. Up until the last kick when they hit the post I don't think we were ever in too many difficulties. It was a very good performance.
"We never had our hearts in our mouths until the last kick when they hit the post.
"Overall, I am delighted for the players and proud of them - they really performed well."
With Bolton winning at Sheffield United, Birmingham beating Leeds and both Barnsley and Burton picking up draws, the win became even more significant.
Coleman added: "Of course you want three points, it is all about the points but sometimes you see performances and the intent isn't there and the meaning.
"That was the case at Bramall Lane, it was a huge disappointment because I hadn't seen that. Today, they responded magnificently well.
"If you let Forest dictate they can hurt you. We didn't do that. We chose our moments wisely and got on top of them first half.
"I can't say that Robbin Ruiter had loads of saves to make because he didn't. The performance was a very good one."