Athletic Bilbao beat Mallorca 4-2 on penalties on Saturday to win their 24th Copa del Rey title and their first since 1984 - ending a 40-year trophy drought in a nerve-wracking final in Seville.

Athletic have been through years of heartache, having lost their previous six consecutive Spanish cup finals and a Europa League final to Atletico Madrid in 2012.

But roared on by around 50,000 fans who invaded Seville and outnumbered Mallorca's supporters at a sold-out La Cartuja stadium which holds 60,000 spectators, Athletic put all their trauma behind to pull out the long awaited victory in a hard-fought final.

Their 23-year-old keeper Julen Agirrezabala, who made a couple of brilliant saves during the game, saved one spot kick in the shootout from Mallorca's Manu Morlanes, while Nemanja Radonjic skied his effort.

Athletic's penalty takers meanwhile were flawless in their execution, scoring four in a row to secure the win that crown a brilliant season under the calm guidance of ex-Barca manager Ernesto Valverde, in which they are also bidding for a top-four LaLiga finish.

"I'm so happy to have made history at this club, the club of my life! I've been dreaming about this for a long time. I've given everything for my family, my friends..." an emotional man-of-the-match Nico Williams told TVE.

"The fans have always been with us and they deserve it, let's enjoy it. It's a dream to win with the club of my life. Everyone can enjoy it now and celebrate!"

The game had finished 1-1 after extra time. Despite Bilbao dominating proceedings with almost 70% of possession, Dani Rodriguez fired in a curling shot after a couple of other efforts had been charged down, giving Mallorca the lead in the 21st minute.

But Ohian Sancet equalised in the 50th minute before Bilbao laid siege to Mallorca's goal, with keeper Dominik Greif working his magic to deny several efforts by the Basque players.

Athletic wasted several other chances to score late on, including Williams hitting the post in extra time.

But a gritty Mallorca outfit, who were aiming for only the second major trophy in their history after their Copa del Rey win in 2003, held strong in defence and were a threat in counter-attacks as well, before finally succumbing in the shootout.

Bilbao are the fourth oldest Spanish club and among three never to be relegated, alongside Real Madrid and Barcelona, while staying loyal to their unique philosophy of only fielding players of Basque origin, considering it a badge of honor.

With their 24th Copa del Rey win, they are is still the second most behind Barca with 31.

"This title is unlike any other," Athletic manager and former player Ernesto Valverde told TVE.

"You only have to see how the stadium was, the fans who came here. I had refused to think about (celebrating) before the final, now I will think about it... What am I gonna do?"