The early pressure on Saints manager Nigel Adkins, whose newly promoted side kicked off bottom of the table following four straight defeats, increased when England striker Darren Bent gave Villa a 36th-minute lead.
But striker Lambert started the south coast club's second half recovery before Nathaniel Clyne and an own goal from Ciaran Clark saw the hosts turn the match on its head.
Lambert then scored his fourth league goal of the season from the penalty spot in added time as Southampton, who had a tough start to the season with matches against last season's top three, won at last.
Villa were outplayed throughout but the manner of their second half capitulation was particular cause for concern for manager Paul Lambert.
Adkins responded to his side's disappointing start by replacing Kelvin Davis, the goalkeeper, with Paulo Gazzaniga, who was handed his Premier League debut following his pre-season move from fourth tier Gillingham.
For 36 minutes, the 20-year-old Argentine was barely troubled as he acclimatised to his new surroundings.
Southampton were the more dominant team during the opening period and, while they struggled to create many clear chances, they controlled the midfield.
Saints captain Adam Lallana, called up into the last England squad, made a series of promising breaks on the left.
And it was from one such move that the midfielder released Rickie Lambert, who curled a right foot shot wide after breaking to the edge of the Villa area.
Adkins also handed first Premier League starts to Gaston Ramirez and Maya Yoshida following their arrival towards the end of the transfer window.
Ramirez was brought in from Genoa for a club record £12 million and quickly demonstrated his ability to drive forward from deep, shooting wide after attacking the heart of Villa's back-four.
Then Lallana finally forced a save from Brad Guzan with an overhead kick as the frequency of Southampton's attacks began to mount.
For Villa, Stephen Ireland attempted to provide a link to the front two of Bent and Christian Benteke but the visitors struggled to make inroads until they were gifted the lead.
Daniel Fox, the Saints left back, failed to prevent Bent reaching a far post cross with the ball breaking to Ireland on the edge of the area.
Then Fox was guilty of switching off completely, allowing Bent to steal in and divert Ireland's shot past Gazzaniga from just five yards out.
Southampton clearly needed to raise their game after the break if they were to force their way back into the game and Lallana and Lambert combined to raise home hopes.
Lallana worked his way down the right hand flank before picking out Lambert, who created space before beating Guzan with a low drive in the 58th minute.
Southampton's tails were up and Clyne added the second in the 63rd minute after neat interplay between Lambert and Ramirez.
Then Jason Puncheon confirmed the home side's superiority with an angled finish that went in off Clark.
The game was effectively over but there was more misery for Villa when Guzan brought down Saints substitute Emmanuel Mayuka and Lambert scored his second from the spot.
Source: AFP
Source: AFP