The fresh-faced young Hammers made it six of the best with another convincing European win in Bucharest’s National Arena.

On an evening when David Moyes ultimately handed debuts to no less than four Academy of Football starlets, West Ham’s energetic, enterprising, entertaining football simply swept away the ragged Romanians to make it a clean sweep of half-a-dozen victories in the UEFA Conference League group stages.

Pablo Fornals’ double-barrelled blast did the damage as he opened the scoring just ahead of the interval and, after debutant Divin Mubama forced a second with a diving header that deflected off joyless Joyskim Dawa early in the second half, the Spaniard then sealed victory on 65 minutes.

Moyes had already arrived in the Romanian capital with the job done following his side’s perfect five wins out of five that had already assured qualification for the last 16 in March, but the Hammers looked unrecognisable from the side that had lost so narrowly at Manchester United on Sunday.

Indeed, only Flynn Downes held onto his jersey as 10 changes saw Moyes hand debuts to two Academy products – 18-year-old Mubama and Oliver Scarles, aged just 16 - while on an equally fresh-faced bench, only veteran keeper Darren Randolph plus youngsters Freddie Potts, Keenan Appiah-Forson and Harrison Ashby had set foot on a first-team pitch before.

That had left fellow rookies Kamarai Swyer, Kaelan Casey, Krisztián Hegyi, Michael Forbes, Regan Clayton and Lewis Orford sitting in the dug-out, eagerly awaiting a call to arms at some stage and Moyes would duly oblige with late run-outs for Swyer and Casey.

Certainly, Mubama had looked keen to take the golden opportunity handed to him and, twice in the opening 20 minutes he came agonisingly close to marking his first-ever appearance in claret and blue with a goal on the European stage.

In the opening exchanges, Downes whipped a right-wing across the face of goal but the sliding Mubama unfortunately could not apply the vital stud and, with West Ham then recycling the ball on the opposite side of the area, Fornals saw his angled shot parried by Stefan Târnovanu.

Fornals also forced West Ham’s first corner before the impressive Scarles fired in an inviting low, left-wing cross that Mubama could only agonisingly steer into the FCSB keeper, who then reacted brilliantly to thwart Fornals’ follow-up, too.

FCSB may have taken the lead at London Stadium in early September but the Hammers still recovered to win 3-1 and, while Moyes men subsequently went on to top Group B with five successive victories, the hosts kicked off in this return tie rooted at the bottom of the group, having forced just two draws to date.

Monday's Halloween defeat at FC Universitatea Cluj had also left the hosts in seventh spot in their domestic league and with their strikers firing first-half blanks, there was little for the locals to cheer apart from Nayef Aguerd’s yellow card for fouling Andrea Compagno.

Certainly, in the sparsely populated National Arena, the Hammers travelling army perched high up behind Alphonse Areola’s goal were making their presence heard above their flag-waving counterparts and, on 35 minutes, those East Enders were left looking high into the Bucharest night, when Târnovanu pulled off another low stop to deny Downes his first goal since his summer signing from Swansea City.

But six minutes before the break, the Hammers did get the goal that their enterprising endeavour merited when Ben Johnson’s defensive clearance sent Fornals racing clear from halfway. 

Continuing to accelerate away from the retreating Romanian rearguard, the Spaniard drilled an unstoppable 15-yarder beyond the helplessly-exposed FCSB keeper to claim his second goal of the season and reward the Hammers with a richly-deserved interval lead.

Only a late goalline scramble denied West Ham a second goal and FCSB coach Mihai Pintilii went for a triple switch at the break, introducing Eduard Radaslavescu, Ianis Stoica and Darius Olaru.

But those three substitutions had absolutely no impact and, after young Scarles had twice threatened on the left side of the area, within 10 minutes of the restart the Hammers had doubled their lead.

This time, Vladimír Coufal charged down the right flank before whipping a cross towards the far post, where Mubama’s diving-header skimmed off Dawa, sending the ball into the net and the Hammers fans, his teammates and the substitutes warming-up down in that corner of the stadium into raptures.

And midway through the half, it got yet better when Fornals claimed his second of the night, when Târnovanu spilled another dangerous Scarles centre and, in his last act of a fruitful evening the six-cap Spain international tapped in from six yards, before retiring as Moyes made a triple substitution of his own.

Ashby, Potts and Appiah-Forson replaced two-goal Fornals, Coufal and Downes and, after skipper Angelo Ogbonna surprisingly arrived in the opposite area, where he ripped a shot into the side netting and the luckless Scarles sent an angled shot just inches beyond the far post, the Hammers boss did indeed call upon two more young debutants.

With dominant West Ham now three goals to the good, Casey and Swyer came on for Johnson and Mubama whose eventful evening had also seen him booked for a foul on substitute Florinel Coman but by now the visitors were home and hosed.

And with Europe comfortably stabled until March, they now prepare to face Crystal Palace on Sunday (2pm), Blackburn Rovers in the Carabao Cup and Leicester City (November 12) before the Qatar 2022 FIFA World Cup break.

FCSB: Târnovanu, Pantea, Radunović, Bouhenna, Dawa, Dulca (Radaslavescu46), Edjouma, Oaidâ (Olaru 46), Cordea (Stoica 46), Popescu (Coman 59), Compagno (Rusu 59). Unused subs: Vlad, Cretu, Dumiter, Boboc, Radaslavescu.

est Ham United: Areola, Coufal (Ashby 66), Johnson (Swyer 76), Ogbonna, Aguerd, Coventry, Downes (Appiah-Forson 66), Lanzini, Scarles, Fornals (Potts 66), Mubama (Casey 76). Unused subs: Randolph, Hegyi, Forbes, Clayton, Orford.

Booked: Aguerd (32), Mubama (70), Scarles (72). Referee: Sascha Stegemann (Germany).

Standings P-W-D-L-F-A-Pts

West Ham 6-6-0-0-13-4-18

Anderlecht 6-2-2-2-6-5-8

Silkeborg 6-2-0-4-12-7-6

FCSB 6-0-2-4-3-18-2