New West Ham boss Gianfranco Zola's 100 percent Premier League record ended with a 3-1 home defeat to Bolton. Twice Bolton took advantage as England goalkeeper Robert Green failed to gather the ball.
Carlton Cole gave the Hammers hope until the visitors ensured the three points with a late free kick.
Zola refused to blame Green for the result.
He told BBC Sport: "Sometimes it happens that you are playing well but you find yourself losing 2-0. It's difficult to accept but it sometimes happens."
"I'm sure that Robert will come back and we are going to be thanking him for saving a penalty or something like that," explained the Italian.
"We have total faith in him and I have total faith in the whole team."
The Irons boss admitted he was hoping for a late equaliser: "I was expecting something to happen in the last few minutes but unfortunately it happened in the wrong way.
"It's been a game in which I learnt a lot and I hope my players did so too," said Zola. "Sometimes to improve you have to go through bad games like this."