Aurelien Tchouameni's long-range strike earned Real Madrid a 1-0 victory over Copa del Rey runners-up Mallorca on Saturday to send Carlo Ancelotti's side 11 points clear at the top of La Liga.
Players boarded a barge known as the 'Gabarra' and sailed 13 kilometres down the river from the affluent town of Getxo to the Bilbao city hall, where the party continued.
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.
Bilbao are the second most successful team in the history of the Copa del Rey, their 23 titles behind only Barcelona's 31, their most recent coming in 2020-21.
Sergi Darder fired the decisive spot-kick as Real Mallorca beat Real Sociedad 5-4 on penalties to book their place in the Copa del Rey final on Tuesday.
Inaki Williams raced back from Africa to face Barcelona in the Copa del Rey and sent Athletic Bilbao into the semi-finals by scoring a crucial goal in their 4-2 extra-time triumph on Wednesday.
Defeat snapped Madrid's 21-match unbeaten run.
"It's a positive result, our play was positive in many moments, and we're in the last 16," Barca coach Xavi told Movistar.
Atletico Madrid progressed with a 3-1 win at third-tier Lugo after Memphis Depay struck twice, while Real Betis were knocked out in a 1-0 defeat by Alaves.
Aurelien Tchouameni's long-range strike earned Real Madrid a 1-0 victory over Copa del Rey runners-up Mallorca on Saturday to send Carlo Ancelotti's side 11 points clear at the top of La Liga.
Players boarded a barge known as the 'Gabarra' and sailed 13 kilometres down the river from the affluent town of Getxo to the Bilbao city hall, where the party continued.
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.
Bilbao are the second most successful team in the history of the Copa del Rey, their 23 titles behind only Barcelona's 31, their most recent coming in 2020-21.
Sergi Darder fired the decisive spot-kick as Real Mallorca beat Real Sociedad 5-4 on penalties to book their place in the Copa del Rey final on Tuesday.
Inaki Williams raced back from Africa to face Barcelona in the Copa del Rey and sent Athletic Bilbao into the semi-finals by scoring a crucial goal in their 4-2 extra-time triumph on Wednesday.
Defeat snapped Madrid's 21-match unbeaten run.
"It's a positive result, our play was positive in many moments, and we're in the last 16," Barca coach Xavi told Movistar.
Atletico Madrid progressed with a 3-1 win at third-tier Lugo after Memphis Depay struck twice, while Real Betis were knocked out in a 1-0 defeat by Alaves.
"This Copa arrived at an important moment, we came through very tricky ties, it's a deserved prize against strong opponents," added the coach