Sadio Mane's injury time winner against QPR on Saturday proved the Saints have the character to qualify for Europe and compete with the Premier League's elite.
It has been said in recent years that the sign of a top side is one that can snatch a win when time seems to be running out.
Ronald Koeman's side did just that with two minutes of stoppage time remaining at Loftus Road, showing his players have the character required to take the club to the next level.
Fight until the end
The Dutchman was understandably delighted to see Mane's strike find the top corner and he was even more pleased that his side kept plugging away until the final whistle.
After they had created numerous chances, particularly in the first half of the match, his players could have been forgiven for thinking it was just not their day.
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This Southampton side though have a different mentality, one that pushes them on in search of one more chance and it paid dividends against QPR.
The great sides of the Premier League era are renowned for their ability to steal three points late on, none more so than a Manchester United team under Sir Alex Ferguson.
Although the Saints are not at the same level as United were back then, there are similarities with the character they are showing this season.
When the odds are against them they do everything they can for each other to achieve their goal which is crucial for any top side.
Koeman will know that although he has a talented pool of players at his disposal, he does not have the wealth of talent afforded to some of his rivals.
What they don't lack in comparison however is an ambition to secure European football for next season.
Koeman has fostered an incredibly tight-knit environment and his players look such a force because of that.
That tight-knit feeling that the players have gives them a belief in their own and their teammates ability to do the job required of them and when they come up against sides who do not share such desire, they are coming out on top.
The 51-year-old manager has said he does not expect to challenge the top two, however after that he does not see why his side cannot finish in any of the positions from third down to seventh.
It is clear to see from their performances on the pitch, that the entire Southampton squad believe they can qualify for Europe next season.
So far, so good
Who would begrudge them that chance if they can keep up the form that has seen them climb to third in the Premier League table with just 14 games to go.
So far this season, the Saints have exceeded expectations but suddenly they are being taken seriously.
If they can follow up Saturday's win with a midweek victory over fellow high-fliers West Ham at St. Mary's, they might just go all the way.