The result takes Forest to third on the table after goals from Chris Wood, Callum Hudson-Odoi and Ola Aina.
"We worked very hard this week. The intensity is what we are focused on. We have to work, and work hard,” said Nuno.
“And we need to improve much more. Nothing has changed since the beginning. We have to keep on going. Believe me, there is no other way. If you get distracted, football doesn’t forgive you.
“Now I’m thinking about Tuesday and the next training session, because that is what’s important. It (the table) doesn’t mean anything now.
“We just have to keep going, keep going. It’s a very long season and every player is going to be needed - we saw that today. It’s a positive moment but we have to keep going.
“All of us should be proud of the way we performed. It was a very good game.
“We started the game well; controlled and dominant. And then we were positive going forward, creating chances.
“The moment of the red card changes everything. It gives us more control of the game. We were already in front and it made it very hard for West Ham.
“But the players understood that even though we had an extra man, we shouldn’t get complacent. They didn’t.
“We went for the game and scored beautiful goals; amazing goals. We should enjoy them, because that is what football is about. It’s a fantastic moment for us and our fans. Let’s keep going and working very hard.”