Video: Manchester United 4 – 0 West Ham (Aug-13-2017) Premier League Highlights
Lukaku, a £75m summer signing from Everton, put the Red Devils ahead with a rising drive off the post after racing onto Marcus Rashford’s pass.
The Belgium international doubled the lead after half-time, glancing in a header from Henrikh Mkhitaryan’s inswinging free-kick.
United teenager Rashford curled against the inside of Joe Hart’s left-hand post before substitute Anthony Martial ended the match as a contest with a slick finish.
There was still time for a fourth, however, as Paul Pogba curled in from distance.
The Hammers offered little going forward in a passive performance, although new signing Marko Arnautovic did flick a header onto the top of the home crossbar at 2-0.