The visitors finished the game with 10 men after the fit-again Aaron Cresswell was controversially shown two yellow cards in the space of less than a minute, and Bilic made clear his unhappiness with the decision to send the full-back off.
"First I would like to praise the team. We showed everything, character, spirit, we deserved to win. The goal we scored was an amazing move from many players. For me it was a penalty on Cresswell and then the second yellow card is very harsh – never a second yellow card, never," he told BT Sport.
"Now that Aaron was back we made a little gamble because we didn't expect him to be totally match fit, but he had a great game. It was straight after the Middlesbrough game that we started to prepare for Palace and also the best system for us that suits all our best players. We came to this system that I really like.
"We need more than one game, more than one win. It is not about the system but much more about the approach and composure we have, how we cover each other and how we close them down. We showed how good a team we are and how good a unit we are."
The victory also gave West Ham their first away points of their campaign and their first league victory on the road since March.