The shooting guard added a three-pointer in the last second of the game to give his side a one-point victory over the Miami Heat.
The 27-year-old told reporters: "I have confidence in every shot I have. When it left, I had a good feeling it would go in. It went in.
"It was for a two, but I told Gerald [Wallace] I wanted to shoot the three to try to win it. Gerald made a great pass at the end, and he got the two-pointer which gave us the opportunity to be in this position.
"Our team made great plays down the stretch, and that is what it takes to win games."
Green finished the game with 24 points, five rebounds, two assists and a block.