The Saints looked to have won their clash with Brighton on Friday night when Cameron Archer swept home from close range.
However that effort was controversially chalked off following a lengthy stoppage.
Having found the net, play was stopped for around four and a half minutes as VAR assessed the build-up to the goal.
They eventually decided that the goal would be ruled out after Adam Armstrong was adjudged to have interfered with Ryan Fraser's cross into the box before Archer's finish.
With Armstrong standing in an offside position, the goal was disallowed.
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As Southampton's players and head coach Russell Martin watched on in disbelief, their goalkeeper Ramsdale was quick to take to social media to express his views.
On X, Ramsdale wrote: "You can not be serious." with a facepalm emoji.
The former Arsenal goalkeeper is currently sidelined with a finger injury and was replaced in the team by Joe Lumley.
The Premier League Match Centre X account then clarified their decision, posting: "The referee's call of no goal was checked and confirmed by the VAR as Armstrong was in an offside position and deemed to be impacting Varbruggen's ability to play the ball."
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It meant that the match ended 1-1 at the final whistle.
Brighton took the lead after 29 minutes when Kaoru Mitoma gave the hosts the lead.
Southampton then found a way back into it with a neat strike from Flynn Downes after 59 minutes.
It was the Seagulls who certainly had the majority of the play and had chances to win the game, but with the VAR call in mind, they were perhaps fortunate to come away with a point.
A draw for Brighton has seen them move up to second in the Premier League table on goal difference.
Meanwhile a win for Southampton would have seen the bottom-placed side move to within touching distance of the sides above them.