Pre-season continued at the London Stadium on Saturday with Andriy Yarmolenko and Tomas Soucek on target for the hosts.
It is now three pre-season wins on the bounce for David Moyes' side following midweek wins over Wycombe Wanderers and Ipswich.
Yarmolenko opened the scoring in the first-half, finding the back of the net after a through ball from Pablo Fornals.
The Bees levelled up after 32 minutes however, Marcus Forss heading home a cross from Rico Henry.
Moyes made seven changes at half-time, Soucek one of them. The January signing combined with Michail Antonio as West Ham retook the lead.
West Ham have two more scheduled pre-season fixtures against Reading and Bournemouth before hosting Newcastle in their opening game of the new Premier League season on Saturday September 12.
