Brighton scored two goals from two shots on target to maintain their unbeaten start to the season with victory at West Ham, who remain without a goal or a point this season.
The Hammers started the second half brightly but were undone when Leandro Trossard latched on to Pascal Gross's flick to seal a third straight league defeat for the hosts.
Aaron Cresswell had a fierce effort well blocked by Joel Veltman, before Robert Sanchez produced two acrobatic saves late on to keep out two Tomas Soucek headers.
The victory for Brighton stretches their unbeaten run to eight games, while West Ham have now had 38 shots in their opening three league games without scoring a goal.