Fernando Hierro's side finish above Portugal in Group B after a 2-2 draw against Morocco in Kaliningrad.
Spain booked a last-16 World Cup clash with hosts Russia after a last-gasp 2-2 draw against already eliminated Morocco in Kaliningrad.
The 2010 champions started Monday on top of Group B but seemed certain to slip below their Iberian rivals in the final table as both matches entered stoppage-time with Portugal and Morocco leading.
Spain went behind when Andres Iniesta and captain Sergio Ramos somehow allowed Khalid Boutaib to seize upon a loose ball and run clear to score Morocco's first goal at the finals since 1998.