Week 20's final La Liga clash pitted Athletic Bilbao against Real Valladolid at San Mames.
The home side had the better of the chances in the first period, but trailed at the interval to a goal from Oscar Gonzalez.
However, Bilbao were level after 65 minutes through Ibai Gomez, before Oscar de Marcos made it 2-1 after 75 minutes.
The home side were not finished, however, as Gomez scored his second late on, before Ander Herrera added a fourth.
Valdet Rama registered a late consolation for Valladolid, but it was a case of too little too late for the visitors as Bilbao continued their unbeaten home record this season.
Read how it all unfolded in Sports Mole's minute-by-minute live commentary of the action below.
BILBAO: Iraizoz; Iraola, Gurpegi, Laporte, Balenziaga; Iturraspe, Benat; Susaeta, Herrera, Ibai; Aduriz
VALLADOLID: Marino; Rukavina, Valiente, Pena, Bergdich; Rubio, Perez, Rossi, Ebert; Oscar, Guerra