Arsenal boss Arsene Wenger was almost lost for words after seeing his side lose for the third time in a row in the Premiership, despite dominating West Ham throughout.
The Gunners rained down efforts on the Hammers goal, but were thwarted at every turn by Robert Green, as the relegation candidates left the Emirates Stadium with a 1-0 victory.
Wenger commented: "It's difficult to say we played a bad game because we should have scored ten and yet we lost the game.
"As long as you don't score there's more pressure on the next player who has a chance. That's what happened.
"It is very difficult to find a logical explanation to our defeat because we produced the performance I expected.
"That is a little bit of the disease we have shown all season - creating, creating, creating and not finishing."
The Frenchman also accepted that the race for fourth place is well and truly on due to his side's ragged recent form.
He added: "For me fourth place was in danger before this game. It is important to keep the focus. I think we will make it, but we have not got to waste any points now."