Pablo Fornals netted either side of half-time as West Ham beat FCSB 3-0 to finish the Europa Conference League group stages with maximum points.
Fornals’ brace and a deflected effort from teenage debutant Divin Mubama ensured the Hammers became the first team in the competition to win all six of their group-stage matches.
David Moyes gave 14 senior players a night off as Declan Rice, Jarrod Bowen, Kurt Zouma and Michail Antonio were rested.
Yet it was still a mature performance from a line-up including debuts for 16-year-old midfielder Oliver Scarles and homegrown striker Mubama, 18, as well as teenage substitutes Freddie Potts, Keenan Appiah-Forson, Kamarai Swyer and Kaelan Casey.
The rookie starters almost combined for an opening goal after 22 minutes, with Scarles whipping in an inviting low cross.
Mubama arrived at the perfect moment to slot the ball home but placed his effort too close to home keeper Ștefan Tarnovanu, who saved with his legs.
Moments later Tarnovanu made a fine save to keep out Flynn Downes after he met a cross from Fornals.
But it was Fornals who broke the deadlock, and bagged his first European goal for the Hammers, five minutes before half-time.
The Spanish midfielder let Ben Johnson’s long ball bounce in front of him on to his left foot before lashing a superb first-time finish past Tarnovanu.
There was more than a hint of offside as Fornals broke clear, but with no flag raised and no VAR at this stage of Europe’s third-tier competition, the goal stood.
Defender Nayef Aguerd was millimetres from a second before the break when his header was cleared off the line by Alexandru Pantea.
Mubama was then inches away from converting another Scarles cross, before the Newham-born teenager’s big moment arrived in the 55th minute.
Downes smuggled the ball out to Vladimir Coufal on the right and his cross was headed home by Mubama, via a deflection off Joyskim Dawa.
The third came from a cross from the impressive Scarles, which Tarnovanu palmed straight to Fornals, who crashed the loose ball into the net to cap a hugely satisfactory night for West Ham.
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