Newcastle took the lead through Isaac Hayden, striking the ball on the rebound from 20 yards past Frasier Forster who was still recovering from the earlier effort.
Gabbiadini equalised after some hard work inside Newcastle's penalty area, but moments later Ayoze Perez restored the away side's lead at the second attempt.
Gabbiadini then brought Southampton level once again, this time from the penalty spot after Florian Lejeune brought down Shane Long.
Change of shape for Saints to mirror Newcastle
Southampton played with both Shane Long and Gabbiadini as they bid to end their goalscoring woes. They haven’t been as adventurous in the final third as previous years, illustrated by the crowd’s groans just a few minutes into the game.
The game’s first chance fell to Christian Atsu, latching onto a cleared corner with a superb first touch but his shot was wide of the near post.
The two teams mirrored each other in their setup, both playing 4-4-2 with one winger specialising in one-one-ones in Atsu and Nathan Redmond, while their opposite wingers in Matt Richie and Dusan Tadic are more playmaker-types and cut inside regularly.
Even the four strikers on the pitch were similar, neither really target men-types which you’ll often find in a two-striker system but all designed to stretch the defences.
All four midfielders are very physical and up for an battle, but Jonjo Shelvey and Mario Lemina have that guile to unlock a defence.
Tadic had Southampton’s first chance, as Redmond was able to get a yard on Jamaal Lascelles to cross at the back post but the Serbian sent a free header over the bar.
It was Newcastle who took the lead in front of the travelling fans, as Hayden blasted home from 25 yards as Forster was still recovering from the previous shot.
Atsu volleyed the ball towards goal, destined for Forster’s bottom-right corner but it was blocked to Hayden who buried the ball in that same corner for his first ever Premier League goal.
The goal meant Southampton had to score a goal at home – something they hadn’t done in eight of their previous nine home games – to get anything out of the game.
However Virgil van Dijk nearly equalised moments later, meeting Redmond’s corner before an onrushing Rob Elliot but couldn’t direct his header on target.
Southampton began to dominate possession but failed to create many clear-cut chances as Newcastle defended well, but Saints didn’t commit their full-backs far forward and the tempo dropped significantly following Hayden’s strike.
Carnage to start the second half
Newcastle started the stronger after the break, as Joselu got on the end of Perez’ cross but could only turn his effort onto the crossbar.
However Gabbiadini ended Southampton’s goalscoring crisis through some sheer persistence.
The Italian got on the end of Redmond’s cross, was forced wide but he worked hard and was able to get cut inside with several markers around him before firing home.
Including Gabbiadini’s effort, five out of the seven goals Newcastle have conceded this season have come between the 46th and 60th minute, something which must worry Rafa Benitez as his side struggle defensively to start the second half.
Benitez’ side bounced back a few minutes later through Perez at the second attempt.
Some neat passing between Shelvey and Richie found Perez in the channel, and at the second bite of the cherry beat Forster at the near post to score his first goal of the season.
DeAndre Yedlin could have been sent off too, he was booked earlier on in the game and should have received a second caution for a late foul on Redmond.
Southampton needed to push for another goal
Southampton brought Sofiane Boufal on for Redmond, presumably to attack Yedlin and try to get a numerical advantage on the pitch, while Perez was subbed off for Mikel Merino as Newcastle set up to contain their opposition.
Interestingly though, Ryan Bertrand seemed to operate in a much deeper position than he has been used in previous years.
Southampton dominated possession throughout, but Bertrand - who can perform in attacking situations – was playing closer to a third centre-back, which was very odd.
Costly error for Lejeune
However Southampton were then awarded a penalty from a swift counter-attack, which resulted in Lejeune bringing down Long in a clumsy challenge.
Gabbiadini put the ball on the spot and smashed the ball into the top corner, a wonderful penalty.
The game suddenly turned very feisty as both sides pushed for a winning goal, forcing several crunching tackles as a nervy 15 minutes remained.
Lejeune then almost made up for his error, meeting Richie’s corner with a powerful header but Steven Davis dropped back on the post to clear the ball off the line before the full-time whistle blew.
Both sides will have been desperate for three points coming into the game, but walking away with one each, neither will be particularly disappointed.