An early brace from Sean Longstaff put Newcastle into a commanding lead early on before a Che Adams strike reduced the deficit for Southampton to 2-1 on the night and 3-1 on aggregate going in at half-time.
It was the first goal Nick Pope had conceded in 11 matches to set up a slightly nervous second half at St James’s Park for The Magpies.
A late sending off for Bruno Guimaraes following a VAR check made things even more nervous for the hosts in the closing stages but they kept their two-goal advantage intact.
Here are the Newcastle United player ratings from the match...
5. Dan Burn - 6
Cut the ball out well when Southampton looked to threaten. No-nonsense playing the ball out. | AFP via Getty Images
6. Bruno Guimaraes - 6
Turned well in the build-up to the opener and was useful on the ball throughout. Came close to settling the tie with an edge of the box strike. Sent off for a reckless challenge late on. | Getty Images
7. Sean Longstaff - 9
Found pockets of space well and was rewarded with an early opening goal. Found a second after being in the right place at the right time. Almost scored a stunning third in the second half. A true local hero performance. | Getty Images
8. Joe Willock - 6
A fine run led to Newcastle’s second but gave the ball away for Southampton’s goal. | Getty Images