The Barcelona man was at the heart of the majority of Spain's best attacks at the Vicente Calderon, and he was rewarded for a fine performance when he swept home the winner from close-range in the second half.
Italy played their part in an entertaining encounter, but Vicente del Bosque's men were good value for a win that is sure to provide a timely confidence boost as they continue their preparations towards the start of the global showpiece in Brazil.
Spain enjoyed the majority of possession in the first half, though Italy went closest to breaking the deadlock when Alessio Cerci's cross-cum-shot deceived Iker Casillas and hit the post.
In an end-to-end opening, Italy went closest to opening the scoring in fortuitous circumstances on four minutes when Cerci's mis-hit cross from the right hand-side of the box looped over Casillas and rebounded off the far post.
Spain responded in kind when Pedro's low drive from 25 yards was well parried by Gianluigi Buffon.
Italian opportunities were proving few and far between, but Pablo Daniel Osvaldo should have done better on the half-hour mark when he collected Claudio Marchisio's neat flick before advancing towards goal and curling a left-footed shot wide.
Spain's relentless second-half pressure finally told just after the hour mark when Silva's attempted one-two with Andres Iniesta fell kindly for Pedro, who squeezed his shot under Buffon - although the Italian may feel he could have done better in keeping the shot out.
