United were always going to be in Friday’s last-16 draw given the first leg result against Sociedad, for whom Manchester City great David Silva was conspicuous by his absence.
The veteran was among five alterations made by coach Imanol Alguacil, who knew their minuscule chances of progressing would only be possible by unsettling the hosts with an early opener.
James gifted them the chance to do just that, with referee Lawrence Visser pointing to the spot after the Welsh winger clattered into Andoni Gorosabel when collecting a pass from United academy graduate Adnan Januzaj.
Oyarzabal stepped up to the spot but the Sociedad skipper sent it into the Stretford End in the 13th minute.