The Barcelona striker pounced his first shot blocked by Portugal goalkeeper Eduardo, but on the rebound, he coolly slotted home with his right foot.
Villa said, '' It was one of my best goals because it got us through to the next round, Keep scoring so we can keep going.''It was enough to put Spain into a last eight showdown on Saturday against the South
Americans, who crushed Japanese hopes in a dramatic 5-3 penalty shoot out earlier in the day. The goalkeeper did well to fist it away and he was in action again soon after with Villa cutting in from the left and fizzing a shot on target.
Portugal were all over the place and Villa rifled another goal-bound in the sixth minute, with Eduardo palming it to safety as he again came to the rescue.It was impressive stuff from Spain, who were playing the slick passing game they are so good at.
Portugal's record of not conceding a goal in South Africa was looking decidedly shaky and Xavi troubled them again by turning and whipping a shot over the bar from a quickly taken corner.
After weathering the early storm, Portugal finally got a look in when Tiago blasted a shot from distance, with Casillas pushing the ball in the air and then having to scramble it to safety as Almeida challenged him.
Portugal were back in the hunt in a finely poised game and they almost broke the deadlock early in the second half when Carlos Puyol got his knee in the way of a Almeida cross and it looped over Casillas' head and shaved the post.
The match started opening up but it was game over for Liverpool's Torres, who was hauled off after 58 minutes with Llorente replacing him and he almost made a spectacular entrance, heading straight at Eduardo.
Llorente seemed to spark Spain into life and seconds later Villa saw a powerful shot squirm past the post before the Barcelona striker demonstrated why he is one of the best in the business.
Another ferocious Villa drive stung the goalkeepers' palms with 13 minutes left as Spain turned up the heat before Portugal's misery was completed when Costa was given a straight red card for elbowing Joan Capdevila.
Spain's alive World Cup quarterfinals at the FIFA in South Africa 2010.