After a goalless first half at Whitley Park, Emerson's cross-cum shot fired Newcastle's youngsters into the lead, the Carlisle-born youngster's first goal at Under-21 level since April 2025 following his recovery from an ACL injury.

United's second-string doubled their lead after the hour mark courtesy of Kouossu's header, the 16-year-old's first goal at Under-21 level, as Robbie Stockdale's side claimed a fourth successive win across all competitions.

The young Magpies, who recorded a 4-1 win against Luton Town in their opening Group D fixture, made six changes from Monday's 3-2 comeback win against Sunderland in the Premier League 2 as Park Seung-soo and Vakhtang Salia, both on target against their local rivals at St. James' Park, featured in the starting XI.

Newcastle's second-string almost got off to a flying start as Emerson's lofted cross from the right flank was spilled by Peterborough goalkeeper Bastian Smith into Kouossu's path but the teenage midfielder's close-range effort was parried by the Posh shot-stopper before Alfie Seldon's rebound was blocked by Noah Freeman.

Newcastle continued their push for an opener as Salia latched onto Seung-soo's pull back, following a positive run from the South Korean winger, but saw his shot blocked by Smith before Emerson's fiercely-driven rebound was blocked out for a corner.

Magpies goalkeeper Roman Dowell, a representative of England at Under-18 level, prevented the visitors from opening the scoring as the 16-year-old, who hails from Boldon, got across quickly to hold Kurtis Simmons' volley at goal following Benjamin McWilliams-Marcano's dangerous cross into the box.

Kyle Fitzgerald, who joined the Magpies' Academy from hometown club Galway United in February 2025, went close to scoring his first Under-21s goal since March as the Irish winger collected the ball on the right flank but, after cutting inside, saw a fierce shot pushed out for a corner by Smith.

Salia, targeting a sixth goal of the season across all competitions at Under-21 level, went close to breaking the deadlock before the half-time whistle as the Georgian striker, a representative of his country at Under-21 level, saw a ferocious drive from distance whistle wide of the right-hand post.

In the 51st minute, Newcastle took the lead through Emerson as the 20-year-old forward, who made his first-team debut for the Magpies during a pre-season friendly against Hull City in July 2024, attempted to cross the ball into the box but saw his delivery sail into the left-hand corner.

Alfie Seldon, who signed his first professional contract with the Magpies last week, went close to doubling the host's lead shortly after the hour mark as the 17-year-old's glancing header from Fitzgerald's teasing cross flew inches wide of the far left-hand post.

In the 64th minute, Newcastle doubled their lead as Kouossu, who joined the Magpies' youth set-up from West Bromwich Albion in the summer of 2024, became the club's youngest goalscorer at Under-21 level since Adam Armstrong in August 2013.

The England Under-16 international, who joined the Magpies' youth set-up from West Bromwich Albion in the summer of 2024, arrived onto Emerson's lofted cross inside the box before guiding a firm header beyond Smith, wheeling away to celebrate in acrobatic fashion.

Salia was unable to net United's third of the night as the 19-year-old forward capitalised on a defensive error from the Posh backline but saw his low curling effort inside the box held by Smith.

Dowell ensured United's hopes of a first clean sheet of the current campaign as the promising 'keeper got across to tip away Simmons' strong drive out for a corner.

Emerson was denied a brace in stoppage-time as the Cumbrian forward got onto Matheos Ferreira's pass in-behind the Posh defence but saw his slotted effort turned around the right-hand post by Smith but the miss would not prove costly as Newcastle's youngsters secured a third consecutive home win in all competitions.

Newcastle United Under-21s are in EFL Trophy action on Tuesday, 3rd November when facing an away trip to League Two side Rotherham United, aiming to qualify for the competition's knockout stages for the first time since 2018/19.

Newcastle United Under-21s: Roman Dowell, Henry Johnson, Kyle Fitzgerald (Kyran Thompson 73), Luke Craggs, Logan Watts, Scott Bailey (c) (Mason Miley 45), Johnny Emerson, Jayden Kouossu, Vakhtang Salia (Kacey Wooster 73), Alfie Seldon (Guy Bloomer 83), Park Seung-soo (Matheos Ferreira 67).

Subs not used: Alex Walpole, Baran Yildiz.