Villa found an unlikely opener and stood resolute in defense but couldn't take all three points on a landmark day for its manager.
Premier League high-flyers Southampton spoiled Paul Lambert's 100th game as Aston Villa manager by snatching a late 1-1 draw at Villa Park.
Nathaniel Clyne, fresh from making his England debut in the recent international break, scored his third goal of the season nine minutes from time to secure a share of the spoils.
Villa spent much of the first half under pressure, but went ahead against the run of play thanks to the persistence of Gabby Agbonlahor, who capitalized on Fraser Forster's error.
The goal was the first that Southampton had conceded in more than seven hours of Premier League football, but it struggled to break down a resolute home back line.
Having snapped a run of six straight defeats with a 0-0 draw at West Ham before the international break, Villa fans grew hopeful of just a second home win of the season as the game entered its final 10 minutes.
But Clyne latched onto a Ryan Bertrand pullback to rifle home and deny Lambert a win as he hit a century of games as Villa Park boss.
Jores Okore made his first Villa appearance since September 2013 after a serious knee injury as part of three changes to Villa's back four, which was quickly put under siege by the visitors.
Southampton came into the game as one of the league's form side after five straight wins and went close three times in the opening 10 minutes as it looked to impose itself on the contest.
The makeshift Villa defense stood firm, however, not allowing Southampton anything clear-cut, while Agbonlahor looked a menace on the counter-attack despite a lack of support.
And the Villa captain duly managed to break the deadlock all by himself on the half-hour.
A heave out of the Villa defense should have been easily dealt with, but Toby Alderweireld left the ball for an indecisive Forster, allowing Agbonlahor to nip in and round the England goalkeeper before slotting into the net.
Sadio Mane drew a flying save out of Brad Guzan as Southampton was unable to even the scores before the interval and Ronald Koeman began the second half with Dusan Tadic closer to Graziano Pelle in an attempt to penetrate Villa's stubborn defense.
It did little to boost the visitor initially, and it could not find a way into the heart of the Villa defense despite dominating possession.
Indeed, Villa should have doubled its advantage in the 78th minute. Andreas Weimann led a swift counterattack that resulted in Agbonlahor squaring for the Austrian 12 yards out, but he launched his shot into the Holte End.
And he was made to pay just three minutes later, England defender Clyne providing perhaps an unlikely source of inspiration as his scorching effort gave Guzan no chance.
The point only moves Villa up to 16th, but draws against two of the league's in-form sides will boost confidence, while Southampton's failure to win leaves Chelsea a dominant six points clear at the top.