Newcastle will feel aggrieved at Craig Pawson's decision to send off defender Fabian Schar in the first half after coming head-to-head with Southampton striker Ben Brereton Diaz.
The Chile international gave Schar a push in the back and Schar reacted by lightly pushing his forehead into Brereton Diaz's, resulting in the striker dropping to the ground.
Pushing and shoving then followed from both sets of players as Southampton wanted Schar to be shown red while the Magpies thought it only warranted a booking.
Pawson's decision to brandish a red was not reversed by the Video Assistant Referee (VAR) and St James' Park erupted into boos every time Brereton Diaz touched the ball.