An outstanding hat-trick from midfielder Saúl Ñíguez ensured Spain saw off the threat of Italy and put them through to Friday's Euro U21s final.
Their opponents will be pre-tournament favourites Germany who defeated England on penalties earlier on Tuesday evening.
Deulofeu stars in tight opening 45 minutes
In a repeat of the 2013 final, Italy were keen to get off to a strong start and took the game to a Spanish team who have looked susceptible to offensive pressure in previous matches. Federico Chiesa cut inside from the left flank before forcing Kepa Arrizabalaga into a low save with his weaker right foot.
After a spell of dangerous crosses flooded the Spanish box, captain Gerard Deulofeu began to get a hold of the game. He released Dani Ceballos who saw a deflected effort fly wide before Deulofeu himself forced Gianluigi Donnarumma to tip over from the resulting corner.
Both sides looked comfortable on the ball during spells of possession and Deulofeu looked the most likely man to create an opening. He fired a snapshot at Donnarumma from range that was comfortably held by the giant shot-stopper.
As the half tipped past the midway point, each team had a similar opportunity within the space of five minutes. Andrea Petanga latched onto a long ball before being thwarted by Kepa. Moments later, that man Deulofeu took hold of a similar clipped ball in behind the defence but slashed wide from a tight angle.
There were various sparks of flair appearing all over the pitch but both sides were crying out for something similar in the final third. Ceballos did produce some neat footwork before releasing Sandro Ramírez who fired over from range. Petanga then stung the hands of Kepa before an even first half drew to a close.
Action-packed start to the second half ignites the encounter
Spain began to gain more influence in the attacking third after the break and they were soon able to forge a breakthrough. Ceballos cut inside and released the previously quiet Saúl Ñíguez. The midfielder trapped the ball in front of him and lashed the opener into the bottom corner just eight minutes after half-time.
A huge task for Italy to overhaul the Spanish starlets soon became a mammoth one just moments later. A neat bit of skill from Ceballos helped him slip away from Roberto Gagliardini before the midfielder hacked his man down to receive a second yellow card and his marching orders.
With Spain poised to go for the jugular, Italy mounted a surge of defiance with a surprise equaliser. Fernando Bernadeschi powered forward from a quick free-kick before releasing an effort that took a slight deflection past Kepa and into the back of the net.
Yet Spain have an abundance of talent going forward and they soon struck again. Saul picked the ball up in space and unleashed a 25-yeard thunderbolt into the top corner to restore Spain's advantage, less than three minutes after conceding.
Saul completes his hat-trick to send Spain through
With the upper hand oncemore, Spain took the tempo of the game up a gear in an attempt not to let the lead slip again. Deulofeu continued to influence the contest and forced Donnarumma into a smart stop from range.
Italy began to appear ragged and loose in possession as a wayward pass fell to Marcos Asensio who fired just wide. Asensio then found space on the left flank, reached the byline and cut the ball back to Saul who lashed home a third and his hat-trick.
As Spain opted to rest their key players, Italy did venture forward one last time but Kepa was equal to Lorenzo Pellegrini's drive. At the other end, substitute Inaki Williams was desperate to grab a goal but saw efforts blocked and kept out by Donnarumma.
Yet the damage had been done and Spain sent out a defining message to Germany ahead of an intriguing final on Friday.