Spain could only manage a point against FIFA World Cup debutants Cabo Verde in their tournament opener, having been blunted by a goalkeeping masterclass from Vozinha.
La Roja hit their straps on Matchday 2, with Lamine Yamal opening his World Cup account in a 4-0 demolition of Saudi Arabia.
A mistake by Uruguay goalkeeper Fernando Muslera allowed Alex Baena to score the only goal at Guadalajara Stadium, as Spain advanced as Group H winners.
Mikel Oyarzabal's brace helped the 2010 world champions record a more comfortable win over Ralf Rangnick's Austria.
Pedro Porro was also on target as La Roja celebrated their first knockout-stage win since that triumphant night at Soccer City 16 years ago.
Better late than never: substitute Mikel Merino celebrates his stoppage-time winner in the Battle of the Iberians.
Unai Simon played his part to keep Cristiano Ronaldo at bay on the Portugal captain's final World Cup appearance.
After Fabian Ruiz broke the deadlock, Charles De Ketelaere's equaliser ended Simon's record-breaking run of 650 minutes without conceding a World Cup goal.
However, super-sub Merino had the last laugh. Here he is soaking up the adulation of the crowd after scoring with his second touch to send his team through.
Spain saved their best performance yet for France, helped by Oyarzabal's laser-guided penalty to open the scoring.
Simon and Co did a fantastic job of nullifying the threat posed by megastar forward Kylian Mbappe and Les Bleus' all-star attack.
Porro's second goal sparked wild celebrations among his team-mates as Luis de la Fuente's men moved to within one win of World Cup glory.
After dominating the regulation 90 against a stubborn Argentina side, Spain finally took a deserved lead when substitute Ferran Torres swept a superb shot into the roof of the net.
Sealed with a kiss: Spain's golden boy proceeded to enjoy his moment with the most sought-after trophy in world football.
Sources: FIFA Official
