Aritz Aduriz struck late on as Athletic Bilbao edged past Gary Neville's Valencia on away goals to reach the Europa League quarterfinals.
Goals from Santi Mina and Aderlan Santos gave Valencia a 2-1 aggregate lead but Aduriz's eighth goal of the competition 14 minutes from time secured progression for Athletic, despite a 2-1 defeat on the night.
Neville ended the night watching from the stands after being sent off by referee Daniele Orsato for arguing about a possible handball in the build up to the visitors' goal.
Valencia trailed 1-0 following Raul Garcia's goal for in the first leg last week but started the stronger side and it took them just 13 minutes to score the opening goal as Santi Mina knocked in a rebound after former Manchester City striker Alvaro Negredo was denied by Iago Herrerin.
Athletic suffered a blow just 25 minutes into the game when captain Iker Muniain was forced off with a hamstring injury.
Seven minutes before the break Neville's side doubled their lead as defender Aderlan Santos headed Jose Gaya's cross beyond Herrerin.
For 70 minutes it looked like Valencia's lead was safe but Athletic, finalists in 2012, pressed for a goal that would give them the lead and Aduriz eventually provided it.
The crucial away goal came when Raul Garcia's delightful flick found Aduriz who had an easy tap in.
After Neville was sent off, Valencia went close through Sofiane Feghouli and Dani Parejo but were unable to find a late winner.