Manchester City boss Pep Guardiola insists West Ham made it difficult for them on Wednesday night.
City cruised to victory via goals from Nathan Ake, Erling Haaland and Phil Foden.
But Guardiola said afterwards: "Every game is hard. The day was so cold and windy.
"We didn't play bad but our structure wasn't great. We didn't score in the beginning but we pushed on. I'm really pleased with five games left.
"This was one of our games in hand and we used it well. On Saturday at 3pm we face Sam Allardyce.
"It's difficult [to break the structure of West Ham]. We tried different combinations down the left and down the right. People kept losing the ball and being anxious and we had to lose that anxiety.
"We dropped a little tonight but not much and we managed to create some chances. It's another three points and we keep going."
On Erling Haaland's Premier League goalscoring record, he added: "It's unbelievable. How many important goals he's scored to win games, we are so satisfied.
"He's a unique person and he's so special. He deserved the guard of honour because it's an incredible milestone. Another day he might break his own record. He's scored a lot of goals!"
