The Hammers won 3-1 with Crysencio Summerville, for the third game in a row, Jarrod Bowen and Mateus Fernandes all scoring before halftime.
Nuno told West Ham TV afterwards: "It was a good performance. In the first half, we started really well.
"The momentum, the energy that the boys put in, the connections, the combinations. We scored, we had good spells of football (and were) dominant in terms of defence.
"And it was a big improvement in the second half in terms of managing the game, managing the tempo of the game. We didn't allow too many situations - they scored but didn't go crazy.
"We kept the shape, kept organised. And in the second half, (we drew strength from) the support of the fans, realising that we were in trouble, that we needed energy.
"When we give, they give back 1,000 times more. So overall, it a very good performance. We are in a tough place. We have a lot of work to do, but this is what we need to do from minute one.
"We cannot afford to lose one moment in our game, that we don't look to score, or we don't look to win our duels. The boys are there."