Nico Williams' late goal finally ended Rangers' Europa League dreams as Athletic Bilbao reached the semi-finals to maintain their hopes of winning the tournament on home soil.
After battling to a goalless draw at Ibrox despite playing most of the first leg with 10 men, Rangers needed a near-perfect performance against La Liga's fourth-place side, and were still in the tie with 11 minutes left.
However, Spain international Williams headed home Oscar De Marcos' beautiful cross to kill Rangers' chances of a second final in four seasons, after Oihan Sancet's penalty in first-half stoppage time broke the deadlock.
Conceding the first goal at that point was a cruel blow for Barry Ferguson's side, but in truth it was no less than Athletic deserved for their first-half dominance.
It was John Souttar who was penalised for running into Maroan Sannadi just as the interval approached, but Rangers did at least respond positively for a spell after the break.
Not helped by injuries to defenders Ridvan Yilmaz and Leon Balogun, they kept the ball better and went agonisingly close to an equaliser when Nicolas Raskin's close-range shot was touched on to a post by goalkeeper Julen Agirrezabala.
There will be plenty of wistful thoughts about that chance, as there will be for a controversial moment when the game was goalless.
Cyriel Dessers was pulled back in the box by Dani Vivian to the extent his shirt was ripped, but the officials deemed the contact as fleeting and there was no Rangers penalty or red card.
But apart from that nervy moment and Raskin's close shave, Athletic were fairly comfortable in defence, as their dream of winning the Europa League at their San Mames home moves a step closer.