Mark Irvine’s accurate prod into the corner shortly after the restart was all that separated the two sides on an evening where chances were hard to come by.
Having taken the lead, Southampton managed to nullify the home side’s threat for the majority of the second half after a first period with little opportunity for either team.
The opening half-hour proved to be uneventful, with Espanyol winger Juli providing Saints’ only scares in that period.
The first of two came as late as the 20th minute when the Spaniard’s dangerous cross was scooped over the bar by retreating defender Ollie Cook.
Marcus Barnes chested down a chipped pass under pressure in the hosts’ area before turning and scuffing a shot that was comfortably held.
That was sandwiched by another opportunity for Juli. This time the winger met a nodded clearance from a corner in the left side of the box with a drive sliced high and wide.
Saints’ other attempt in the half arrived with ten minutes remaining when the ball was pulled back as far as a trialist playing in defence, whose long-range hit flew comfortably wide.
The only moment of worry in the first 45 minutes came in the dying stages of it when Southampton ‘keeper Nick Croucher was caught out of position when chasing the ball near the corner, allowing Cristo to curl a shot from an acute angle that fortunately crashed into the side-netting.
The visitors didn’t allow the tempo of the restart to repeat the beginning of the match as they latched onto the Catalans’ poor effort at a clearance before Irvine turned past a challenge in the box and prodded home the opener.
Espanyol were starved of chances until there was little more than 20 minutes to go in the match. A cross deflected perfectly for the well-placed Melendo to nod in but the youngster’s header looped well over the crossbar.
Alex Lopez was afforded a charge through the centre of midfield but his 25-yard hit was palmed wide by Croucher.
Southampton managed to hold on for the remainder of the affair, securing a pleasing victory to return to England with as the 2014/15 campaign approaches.
RCD Espanyol U18s: Pedro Luis (Ruben 30), Labiano (Soria 46), Kike (Sarimento 30), Max (Alex Lopez), Melero (Iago 46), Patrick (Melendo 46), Juli (Gual 46), Alfredo (Melero 46), Cristo (Ecija 46), Rivas (Campuzano 71), Kike Sanchez (Entrena 46).
Southampton U18s: Nick Croucher, Colm Deasy, Ollie Cook, trialist (Josh Debayo 46), trialist, Armani Little, Joe Lea, trialist (Alfie Jones 54), Mark Irvine (Carel Kayembe 54), Dan Demkiv, Marcus Barnes. Unused substitutes: James Needle, Richard Bakary.