Lewis Miley’s first goal of the season at under-21 level broke the deadlock for the visitors at the Amex Elite Football Performance Centre before Magpies midfielder Lucas De Bolle was sent off towards the hour mark after receiving a second bookable offence.

Despite a courageous defensive second half display, United’s youngsters suffered a sickening blow in the seventh minute of stoppage-time following O’Mahony’s scrappy close-range finish.

Ben Dawson made four changes from their previous Premier League 2 clash against their Manchester City counterparts as De Bolle, who spent the 2022/23 season on loan at Scottish League 1 side Hamilton Academical, was named in the starting XI as well as Charlie Wiggett, Josh Scott and Kyle Crossley.

United’s second-string began the contest in bright fashion as Lewis Miley, who became Newcastle’s youngest ever Premier League debutant after featuring in the Magpies’ 1-1 draw at Chelsea on the final day of the 2022/23 season, combined neatly with Amadou Diallo before the 17-year-old’s low drive was pushed away by Brighton goalkeeper Killian Cahill.

Newcastle goalkeeper Jude Smith, who joined the Magpies from East Fife in the summer of 2022, was forced into action as the Scotland under-21 international pushed away Louis Flower’s fierce drive towards the left-hand post away for a corner.

Lewis Miley went close to netting an impressive free-kick as the England under-19 international’s curling set-piece from the edge of the box was clawed away by the alert Cahill.

The Stanley-born teenager continued to create United’s best goalscoring opportunities and was denied again by Cahill after a danegrous combination between Diallo and Josh Scott resulted in the latter dragging the ball into Miley’s path, whose first-time effort was blocked by the feet of Cahill.

In the 34th minute, however, Miley netted a goal he and his Newcastle team-mates deserved. After Jamie Miley’s corner was only half cleared towards the edge of the box, his younger brother was on hand to lash a vicious drive beyond Cahill.

Newcastle were dealt a tough blow in the 56th minute as De Bolle received his marching orders after picking up a second yellow card to the frustration of the Magpies squad.

The visitors were unfortunate not to double their advantage minutes later, though, as Blyth-born forward Dylan Stephenson latched onto Jamie Miley’s pass inside the box but could only fire a tame effort into the side-netting.

Newcastle’s lead remained in tact although the young Magpies blew a sigh of relief after Jack Hinchy’s low cross was turned onto the foot of the right-hand post.

Smith produced a string of key saves in the closing stages to maintain Newcastle’s one-goal advantage, most notably turning away Joshua Duffus’ powerful first-time effort inside the box whilst substitute defender Charlie McArthur produced a heroic last-ditch challenge to block Marcus Ifill’s attempt on goal.

However, in the 97th minute, Brighton levelled the clash as O’Mahony drew the Seagulls level, bundling the ball home inside a crowded six-yard area following a teasing cross from the right flank.

Newcastle United Under-21s return to Premier League 2 action on Friday, 29th September when they host their Nottingham Forest counterparts at Whitley Park (kick-off 7pm BST).

Newcastle United Under-21s: Jude Smith, Charlie Wiggett, Cathal Heffernan, Remi Savage, Josh Scott, Jamie Miley (c) (Ellis Stanton 72), Lucas De Bolle, Lewis Miley, Kyle Crossley (Nathan Carlyon 59), Amadou Diallo (Charlie McArthur 85), Dylan Stephenson (Ben Parkinson 72).

Subs not used: Will Brown.

Photograph courtesy of Brighton & Hove Albion Football Club