The midfielder struck the only goal of the game at the City Ground.
Doucoure declared afterwards: "It feels amazing! We had a perfect game plan today and we played brilliantly. All the team worked hard. I think we deserved the win – we created so many chances.
"Obviously, I did well in the end in the last minute – I believed that I was going to score today. The ball arrived at the right time, it was the perfect ball and I made the perfect run. The finish was top as well!
"I love this club. I tried to play well. I met some kid before this week and he asked me to do a celebration if I scored, so that was for him.
"Sometimes you think you are going to score, I had that today. It was a top week for us. I think we dominated them from the first minute: we won the tough challenges, we controlled the ball, we created chances. I think we needed to score some goals, it came very late but I think everyone is going to take that win!"