Manchester United shook off a rusty first half to turn FCSB over and progress through to the knockout stages of the Europa League.
Ruben Amorim was bold in his substitutions and the decision to send on Amad Diallo and Alejandro Garnacho at the break changed the game.
From then on United turned the screw and goals from Diogo Dalot and Kobbie Mainoo ensured a routine victory away in Bucharest.
Amorim made five changes to his line-up and while he is still trialling players in different positions, he is continuing to grind out key results and this certainly was one of them.