Despite boasting the lion's share of possession in the opening stages, it was FCSB who worked the first openings on goal. Andrea Compagno forced a smart stop out of Alphonse Areola inside the opening five minutes, before the Italian was on hand again to flick Andrei Cordea’s corner over the bar from close range.
West Ham couldn’t say they hadn’t been warned by FCSB, and it was the 3000-strong travelling contingent who celebrated an opener. Darius Olaru’s lung-busting run from deep resulted in his inch-perfect ball across the six-yard box being slammed home at the far post by Cordea to hand FCSB a HT lead.
Considering West Ham were trailing, there was limited urgency to their play, but they were given a get-out-of-jail-free card when a collision between Maxwel Cornet and Stefan Tarnovanu saw West Ham awarded a penalty, which after a lengthy stoppage for treatment to Cornet, Jarrod Bowen duly converted.
With 20 minutes left, that equaliser breathed new life into the Hammers and another of David Moyes’ substitutes almost poked West Ham in front seconds after the equaliser, but his effort trickled wide of the post.
The pressure did eventually bear fruit for West Ham though, when in rather fortuitous circumstances, the ball fell kindly to Emerson Palmieri on his Hammers European debut and his fierce effort squirmed beneath a desperate Tarnovanu.
In truth from then on it was rather straightforward for West Ham, who wrapped up three points to open their UECL campaign through Michail Antonio and inflicted an 11th-straight winless game on English soil on FCSB.
Flashscore Man of the Match: Flynn Downes (West Ham)
See all the match stats on Flashscore.
In other fixtures:
Slavia Prague missed a last-minute penalty in Turkey as they could only come away with a 1-1 draw with Sivasspor.
In Group E, AZ Alkmaar grabbed a 1-0 win over Ukrainian side Dnipro-1, who hosted the match in a neutral venue while tiny Liechtenstein's Vaduz gained an opening point, drawing 0-0 with Cypriot side Apollon.
In Group F, two goalless draws were had. Molde - Gent and Shamrock Rovers - Djurgarden.
In Group H, Basel won 3-1 at home over Armenian side Pyunik Yerevan and Slovan Bratislava and Lithuanian side Zalgiris played out a 0-0 draw.
