The Magpies took an 11th minute lead at the Saints' Staplewood Football Development & Support Centre through skipper Mackenzie Heaney.

The England under-17 international - recently back from a shoulder injury - curled a 20-yard free-kick beyond Adam Parkes.

But, following a spell of sustained pressure from the home side, Callum Slattery levelled from the penalty spot in the 38th minute, although Otto Huuhtanen dived the right way.

Then two minutes later, a trialist scored a fine individual goal to give the Saints a half-time lead.

But United came out fighting at the beginning of the second period and quickly levelled through Watts, who was playing in an unfamiliar position as a central striker.

He received a pass from Callum Smith and drilled the ball home. 

With the final kick of the game, Southampton almost grabbed a dramatic winner but Huuhtanen saved Will Smallbone's long-range effort before substitute Jonathan Afolabi fired over from the rebound. 

Newcastle have now won one, drawn one and lost one of their three Under-18 Premier League group three play-off matches.

Newcastle United Under-18s: Otto Huuhtanen, Craig Spooner, Gideon Adu-Peprah, Matthew Longstaff, Ben Kitchen, Lewis Gibson, Owen Gallacher, Daniel Lowther (Elias Sorensen 68), Kelland Watts, Mackenzie Heaney, Callum Smith.

Subs not used: Yannick Aziakonou, Mo Sangare, Jack Robson.