Gianfranco Zola said the 3-0 win against Hull was an important victory for West Ham, who have now climbed to 13th in the Premier League.
The Italian was impressed with his team's performance at Upton Park against a nervy City side which took just three minutes to break through.
Valon Behrami scored his first Premier League goal of the season for the Hammers to not only give them a great start but put West Ham in good stead for the win, said Zola.
"It was such an important game for us. I think the way we started basically determined the way the game's finished," he told Sky Sports.
"It's been a fantastic start with the goal and the many chances. I'm very, very pleased with the three points.
"It was so important to make them understand that today wasn't their day and the players have been fantastic, total credit to them because it wasn't easy.
"Fortunately they were fired up today and their performance was excellent."
The Tigers did not do themselves any favours when Craig Fagan was sent off for two bookable offences and Julien Faubert's defence-splitting pass found Carlton Cole who slotted home in the second half.
Faubert rounded off the rout in stoppage-time and Zola believes the result puts them in good shape for the impending trip to Old Trafford on Tuesday to face Manchester United.
"It is a tough game obviously because we are playing the champions and they are always a difficult team to play against but we go there with confidence as well," said the ex-Chelsea striker.
"We can come in from two good results and the players are lively so we'll go there and see what happens."
He added: "The fixtures that we have at home are the games that we can win, but the away games are very difficult so we will have to be very focused, that's why I was saying to the players we need to maintain the focus because if we perform like this we're going to be alright but we need to keep performing like this."