After a goalless first-half, Michael Ndiweni - who signed his first professional contract with the Magpies in July - sent United's youngsters ahead in Algorfa before Enzo Roco's header drew the La Liga side level.

In a physical encounter in the hot Spanish climate, Joe White's low finish regained Newcastle's lead in the closing stages against the senior outfit, who held Champions League winner Real Madrid to a 2-2 draw in January, before holding firm to record an impressive victory.

The first goalscoring opportunity fell to United's second-string as Dylan Stephenson, who joined the Magpies' Academy at the age of 14 from Newcastle City Juniors, latched onto a diagonal lofted cross before his fierce volley flew narrowly over the bar.

Elche, who finished 13th in the Spanish top-flight last term, went close to breaking the deadlock as Branislav Knežević connected with Josan's cross from the right flank but the Serbian teenager's deft effort flew wide of Will Brown's front post.

Josan produced another dangerous cross minutes later as the ball flashed teasingly across the face of goal from the right wing but failed to find an Elche attacker inside the penalty area.

Stephenson, who recorded 15 goals for Newcastle's second-string in all competitions last season, created another chance in front of goal, controlling Lucas De Bolle's pass before the teenager's strike flew past the target.

Remi Savage, who joined the Magpies' youth set-up in the summer of 2021 from boyhood club Liverpool produced a vital last-ditch challenge to prevent Pere Milla from opening the scoring.

The 20-year-old centre-back's pass was intercepted by the one-time Catalonia international but the former atoned for his error to block the striker's effort away for a corner.

At the half-time break, Newcastle made ten changes to their side, with Irish defender Alex Murphy making his debut for United’s under-21 side after joining from hometown club Galway United earlier this month. 

Teenage left-back Jordan Hackett made his official debut for the Magpies' second-string, following a successful trial in May, along with James Huntley - who joined Newcastle's Academy as an eight-year-old in 2012.

One of the substitutes, Ndiweni, made an instant impact as the 18-year-old, who scored 14 times for United's under-18s last term, broke the deadlock in the 50th minute.

After dispossessing Josema towards the halfway line, the Throckley-born striker raced through on goal before cooly slotting the ball beyond Édgar Baría with the outside of his right foot.

Newcastle aimed to preserve their advantage as Elche pushed forward in attack, with Magpies left-back Matt Bondswell - who made his first-team debut debut during a pre-season friendly at Doncaster Rovers in July 2021, importantly blocked Johan Monica's vicious drive at goal.

However, in the 70th minute, Newcastle found themselves back on level terms Enzo Roco’s header from Tete Morente’s corner nestled into the bottom right-hand corner.

Teenage goalkeeper Max Thompson - a representative of England at under-18 level - produced an impressive save to deny Raúl Guti, tipping the midfielder's striker onto the inside of the far post before the ball was cleared to safety.

In the 79th minute, Newcastle netted their second goal of the afternoon through White's splendid finish.

The attacking midfielder, who spent the second half of the 2021/22 season on loan at League Two Hartlepool United, picked the ball up on the right wing before, after cutting inside, fired an acute, low effort into the bottom right-hand corner.

In the closing stages of the friendly contest, Thompson was on hand to maintain United's one-goal cushion as Guti could only guide his close-range header straight at the 17-year-old shot-stopper, who comfortably held the goal bound attempt.

Newcastle United Under-21s return to pre-season action on Wednesday, 20th July when they face their Blackburn Rovers counterparts at Rovers' Academy (kick-off 2pm BST).

Newcastle United Under-21s: Will Brown (Max Thompson 46), Harry Barclay (Josh Stewart 46), Charlie Wiggett (Niall Brookwell 46), Remi Savage (Alex Murphy 46), Jordan Hackett (Matt Bondswell 46), Jamie Miley (Nathan Carlyon 46), Lucas De Bolle (James Huntley 46), Dylan Stephenson (Joe Oliver 46), Josh Scott (Kyle Crossley 46), Santiago Muñoz (Michael Ndiweni 46), Cameron Ferguson (Joe White 32).