The Magpies set up a St. James' Park date with Swansea or Wolves thanks to a 4-1 victory on the South Coast, with Owen Gallacher, Lewis McNall and Callum Smith on target alongside an own goal from Portsmouth skipper Theo Widdrington.

Dave Watson's side dominated the early exchanges, with Smith and Mo Sangare both seeing shots saved by Pompey goalkeeper Jack Collins.

A couple more long-range efforts flew off target and, with Newcastle getting plenty of joy on the left, Smith fired across the six yard box but nobody could get a touch to take it in.

Matty Longstaff forced another save from Collins before the home side began to find their feet and Harvey Bradbury headed just wide of Nathan Harker's goal.

Then Gallacher struck, cutting in from the right before passing the ball into the far bottom corner.

Pompey responded well, though, and after Widdrington - son of former Southampton man Tommy - was denied, they soon levelled through Tommy Scutt, who arrived from deep to turn the ball home.

The game then became somewhat stretched as Portsmouth built up a head of steam, only for Newcastle to regain the lead against the run of play when Lewis McNall - making his first start since September after recovering from an ankle injury - met Smith's cross.

Curly-haired wideman Smith was causing havoc for the Magpies and he fired over at the beginning of the second half, but then laid on United's third; his cross was turned into his own net by the unfortunate Widdrington.

It was nearly four when McNall rounded Collins but could only find the side netting. However, Smith then rounded off the scoring as he got the goal his performance deserved.

Harker's long clearance wasn't dealt with and Smith nipped in to ensure Newcastle's passage into the next round.

Newcastle United Under-18s: Nathan Harker, Craig Spooner, Kieren Aplin, Matty Longstaff, Owen Bailey, Lewis Cass, Owen Gallacher (Dan Lowther 81), Mace Goodridge, Lewis McNall (Thomas Allan 79), Mo Sangare, Callum Smith (Adam Wilson 84)

Subs not used: Otto Huuhtanen, Yannick Aziakonou

Pic: Colin Farmery / Portsmouth FC