First half goals from Said Benrahma and Jarrod Bowen gave West Ham an ultimately unassailable 2-1 lead, which saw them seal progression from group B, though they still are yet to seal top spot officially.
Benrahma's spectacular free kick in the 14th minute gave the hosts the lead, with the Algerian sending the ball into the top left corner from just outside the box with deadly precision.
Bowen quickly doubled the ascendancy on 30 minutes with an emphatic finish from the edge of the Anderlecht penalty box as the Hammers raced to a 2-0 lead by half-time.