Dylan Stephenson had opened the scoring for the young Magpies, finding the target after a flowing move to put Elliott Dickman's in front early on at a rain-soaked Whitley Park, but Dominic Ballard levelled for the Saints shortly after.

Nico Lawrence's thumping header then put Dave Horseman's side in front, but United responded well after the restart, with Isaac Westendorf racing clear to fire home.

And White's stunning late intervention towards the end of a frantic encounter sealed the win for the hosts, whose unbeaten run in the Premier League 2 now stretches to five games.

It took just four minutes for United to craft a well-worked opener. After Jack Turner pulled one wide for the visitors, Dickman's youngsters launched an attack on their own and worked the ball into White in the middle, 30 yards from goal. The Carlisle-born midfielder showed good composure to pick out the unmarked Stephenson, whose unerring first-time finish found the bottom right-hand corner.

It was an enterprising start from the hosts in tricky conditions on Tyneside, but after Westendorf slipped when through on goal, the Saints fired a warning of their own. Ballard nodded down a cross at the far post for Turner, whose initial effort was cleared. Southampton's captain pounced on the rebound, but Niall Brookwell produced a timely headed clearance just in front of his own goalline to protect Newcastle's lead.

With 17 minutes gone, though, Southampton did grab a leveller through the dangerous Ballard. The goal owed much to some good work down the right from full back Zuriel Otseh-Taiwo, whose low cross was picked up by Ballard and turned beyond Will Brown in the United goal.

Brown had not had a great deal to do prior to the equaliser but was called into more meaningful action soon after as the Saints moved into the ascendency. They continued to push after Thierry Small saw a shot charged down, with Turner picking out Samuel Amo-Ameyaw in the area, but Brown did well to get himself in the way of the goalbound effort.

Then came a brief spell of pressure from the Magpies, who struck the woodwork through Jamie Miley's header. Just seconds later, after White had flashed a free kick across the face of goal, James Huntley took aim, but saw his low drive parried by goalkeeper Oliver Wright.

But it didn't take long for Southampton to respond. Brown had already made a save from the onrushing Kamari Doyle but the United stopper could do nothing about Lawrence's excellent header, as the towering centre back rose highest to meet Doyle's corner from the right with just under ten minutes to go until the break.

With the rain still falling in Benton, Newcastle began with greater purpose in the second half, with White again picking out Stephenson on the left. After the forward was fouled, White took responsibility for the free kick just outside the Saints' box, but his low strike didn't make it past the wall. A couple of minutes later, White's cross found Alex Murphy in the box, but the centre half planted his header straight at Wright.

White's deliveries caused the visitors some problems in the second half, and another free kick just before the hour almost heralded the second goal his side craved. It was swung in from the right flank and towards Brookwell in the six-yard box, but the former Liverpool man couldn't quite turn it in.

Moments later, though, Dickman's charges were rewarded for their strong start to the half with the leveller. It came from Westendorf, who made his return from injury against Lincoln City in midweek, and owed much to the frontman's pace as he ran clear of the Southampton backline before prodding his finish underneath Wright.

Dickman introduced recent signing Amadou Diallo from the bench for the final 25 minutes and the ex-West Ham youngster almost created a goal seconds after entering the fray, spotting the overlapping Huntley to his left, but the midfielder's cross-shot was palmed to safety.

Though the final 20 minutes were a little cagier, the energetic Diallo did provide a few threatening contributions for his new club - including winning the free kick for the game's decisive moment.

It was Diallo who nipped in and won possession before being fouled on the edge of the area, with White again claiming the dead ball. From 25 yards, his free kick was perfect, clipping the post on its way into the top right-hand corner to settle an entertaining clash in fine fashion.

Newcastle United Under-21s: Will Brown, Harry Barclay, Matt Bondswell, Jamie Miley, Niall Brookwell, Alex Murphy, Josh Scott (Jordan Hackett 90), James Huntley (Nathan Carlyon 70), Isaac Westendorf (Amadou Diallo 65), Joe White, Dylan Stephenson.

Subs not used: Aidan Harris, Charlie Wiggett.