The Belgium international striker needed less than five minutes to open the scoring his latest outing and earn himself a standing in an elite club.
In becoming a top-flight centurion, Lukaku has become the first Belgian to reach that milestone and the youngest foreign player in Premier League history to hit the mark.
He never managed a Premier League goal for Chelsea, having seen game time limited during a frustrating spell with the Blues.
Lukaku was, however, to prove his worth with the Baggies in 2012-13, netting 17 times during a productive loan spell.
Another 15 followed at Everton the following year, before they made that move permanent and were rewarded with another 53 strikes across three campaigns.
United then invested £75 million in Lukaku during the summer transfer window of 2017 and have seen him hit the target 15 times in the Premier League, and on 26 occasions across all competitions.
Only four players have made it to 100 Premier League goals at a younger age than Lukaku, and they are all iconic figures of the English game.
5 – Romelu Lukaku is the fifth youngest player to score 100 Premier League goals.— OptaJoe (@OptaJoe) March 31, 2018
Michael Owen (23y 134d)
Robbie Fowler (23y 283d)
Wayne Rooney (24y 100d)
Harry Kane (24y 191d)
Romelu Lukaku (24y 322d)
United will be hoping that there are many more to come from their talismanic No.9, with Lukaku having shown that he is capable of leading the line for an elite club.
He has endured the odd dip in form this season but has delivered when it matters and can now begin working his way towards the next 100 efforts of a remarkable club career.