The Saints' hopes of obtaining a successive PL victory for the first time since February 2022 were quickly quashed when the high-flying Cherries grabbed two quick-fire goals to put themselves firmly in the driving seat.
It took until the 14th minute for the visiting side to mount their first spell of pressure, and from there, they quickly capitalised when Ryan Christie unpicked the Southampton backline with an exquisite angled ball that allowed Dango Ouattara to glance home.
Two minutes later, Christie was at it again, as the Southampton defence was caught on their heels and slow to apply pressure, allowing the Scottish international to take full advantage from outside the box, drilling in a precise left-footed finish.
With a two-goal cushion, Bournemouth coasted their way through first-half proceedings and Southampton’s afternoon threatened to sour further before the break.
Antoine Semenyo jinked his way into the box but Aaron Ramsdale responded well to block Ouattara’s attempt from a narrow angle.
Semenyo’s trickery continued to be a thorn in Ivan Jurić’s side in the second half, as he weaved his way through the Southampton defence, only for Ramsdale to turn away his effort.
Moments later, the Saints keeper was forced to bail out his side once again, this time palming Christie’s near-post header away to safety as it threatened to cross the goal line.
Against the run of play, the game took an unlikely twist when the Saints halved the deficit with just under 20 minutes remaining.
On the back foot for so long, Southampton’s persistence was rewarded when Kamaldeen Sulemana rifled through the goalmouth to breathe fresh life into the contest.
However, after Kyle Walker-Peters almost unintentionally restored Bournemouth’s two-goal advantage with a back-header that threatened to loop over Ramsdale, substitute Marcus Tavernier finally delivered a third Bournemouth goal, cutting onto his left foot before applying a powerful finish.
The result sees Southampton succumb to a seventh-successive PL defeat on home soil, while Andoni Iraola’s side continue their push for a European spot, extending their longest-ever unbeaten away run in the PL to seven matches in the process.