A police officer suffered heart failure as fans from Athletic Club and Spartak Moscow clashed outside the San Mames on Thursday evening.
Inocencio Alonso Garcia suffered a heart attack whilst on duty during the violent clashes, which saw more than 500 officers deployed for the Europa League second leg.
Five arrests were made as groups of Russian fans carrying weapons, clashed with home supporters, leading to Spanish Prime Minister Mariano Rajoy condemning the action.
The clashes came on the same day a Russian man was arrested for attacking an England fan during Euro 2016, whilst travelling to the game in Bilbao.
President Rajoy offered condolences to the family and friends of the policeman,
Bilbao police also paid their respects to the officer. “Our condolences to colleagues, friends and relatives of the Ertzaina who died in active service,” the force said in a tweet.
Despite the pre-match violence, the game still went ahead as Athletic progressed with a 4-3 win on aggregate.
A fantastic first half showing last week saw Athletic lead 3-1 ahead of the San Mames clash but it was Spartak who would strike first in Bilbao, Luis Adriano heading home.
Enric Saborit showed great feet in the second half to clip the ball up for Xabier Etxeita whose excellently placed header levelled things up.
Lorenzo Melgarejo won the game for Spartak with a close range finish after rounding Iago Herrerin but Athletic will be in Friday’s draw.