West Ham moved into the top six bracket in the English Premier League after beating Everton 1-0 on Sunday evening.
Angelo Ogbonna scored the all-important goal in the 74th minute, with the host failing to respond.
The win also saw the Hammers equal a club record of seven away matches unbeaten.
The hosts were the better side in the opening half, dominating their visitors for long periods but failed to make any meaningful attempt on goal.
Both teams had chances to find the back of the net but could not, with Tomas Soucek's goal correctly ruled out for offside as the two teams went into the break still tied at 0-0.
The hosts picked from where they left in the second half, but a resilient West Ham kept them at bay for long.
With all to play for in the final 20 minutes, the home side appeared to be the side likely to snatch a winner.
But with roles reversed from the first half, West Ham took their only chance as Ogbonna glanced a header past Jordan Pickford from a corner ball.
The win saw the visitors move above the hosts in the Premier League standings into sixth, extending their away unbeaten run to seven games.