The match represented the first final between the two great rivals in their current guises.

Played 350 days later than initially scheduled because of the coronavirus pandemic, La Cartuja in Seville played host to one of the most significant finals in the competition's history and La Real came out on top in the long-awaited encounter.

The first all-Basque Copa del Rey showpiece since 1927, it was perhaps fitting that someone who has played for both teams was central to the match's major moment of contention, as Inigo Martinez was sent off for the concession of a penalty, only to be hauled back on following a VAR (video assistant referee) check.

The former La Real captain's blushes were not completely spared, however, as Oyarzabal – wearing Los Txuri-Urdin's armband – dispatched the spot kick.

While Athletic desperately sought a late equaliser, Marcelino Garcia Toral's men lacked the invention to force extra-time, but they will have another bite at the cherry on 17 April (AEDT) when they face Barcelona in the 2020-2021 final.

Establishing any form of control proved difficult for either side in a frenetic opening half that was exacerbated by the downpour in Seville.

It was not until the 33rd minute that either goalkeeper was forced into necessary action, as Athletic centre-back Martinez let fly from distance and saw Alex Remiro tip over in spectacular fashion – both players featuring against the teams whose academies they graduated from.

Athletic survived a scare at the other end soon after, with Yeray Alvarez managing to cut out Andoni Gorosabel's right-wing cross as Alexander Isak waited for a simple finish.

Martinez avoided conceding a penalty soon after the restart, with his handball deemed to be just outside the 18-yard box.

He did not get so lucky just past the hour, though, when Martinez clumsily tripped Portu as he looked to latch on to a throughball.

The red card flashed in his direction was soon overturned on review, but Oyarzabal was not as forgiving, lashing an emphatic penalty past the helpless Unai Simon.

There proved to be no way back for an Athletic side, which was generally toothless throughout.