While troubled Southampton began the day rooted to the foot of the table, Everton seem to have put their slow start behind them following a five-game unbeaten stretch.
With Ashley Young making his 400th PL start, the two sides were easy on the eye, taking turns of possession in midfield, and for much of the half, goalmouth activity at either end was scarce.
Southampton, however, did begin to show some attacking intent, gaining momentum as HT approached.
Flynn Downes threaded a ball from midfield through the Everton backline, and after slipping past Young, Cameron Archer dragged a low attempt wide across goal before a Saints corner then saw Taylor Harwood-Bellis head wide from close range.
The second half would prove to be a more open affair. Everton’s Orel Mangala forced an awkward save from Aaron Ramsdale, with the Southampton keeper parrying over a strike from just outside the area in unorthodox fashion shortly after the restart.
The hosts’ best hopes of prising an opening appeared to rest on Archer’s ability to penetrate the Toffees' defence, and after Archer had earned his side a free-kick, Harwood-Bellis' shot ricocheted wide.
Everton were denied at point-blank range when Michael Keane’s header from six yards was somehow kept out by Ramsdale, with the ball threatening to squeeze in off the upright.
Neither side appeared likely to break the deadlock with a point apiece looking the most likely outcome but the game finally burst into life with five minutes remaining.
Everton substitute Beto rattled the crossbar with a header, and with their hearts still in their mouths, Southampton immediately broke upfield where Yukinari Sugawara’s square ball was swept in by Armstrong.
Despite jubilant scenes, St. Mary’s was stunned moments later when Beto breached the offside trap to slot in, but after a lengthy VAR review, Everton’s would-be equaliser was dramatically chalked off.
Everton’s desperate advances in added time proved fruitless as Southampton claimed their eighth home PL win over the Toffees in 11 matches, easing the pressure on Russell Martin, whose side at least temporarily move off the bottom of the table.
As for the Toffees, defeat leaves them 16th, four points clear of the drop zone.
Flashscore Man of the Match: Taylor Harwood-Bellis (Southampton)