Here, Sports Mole analyses how the game was won so emphatically on the South Coast.
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On target: 11
On target: 4
Was the result fair?
Just about. Early impressions had suggested that it would be an even encounter, with both sides enjoying clear-cut chances in the opening stages, but Aston Villa never recovered after conceding within minutes of Benteke spurning a fine opportunity.
They had plenty of senior figures at the back, including goalkeeper Shay Given, but none of them felt like taking responsibility and being the calming, assuring presence that Villa needed in order to stem the tide of goals.
"The last two games our start was very poor. We have to change that. The beginning of the game is important." This was the message from Ronald Koeman to his Southampton team prior to kickoff Yet, the Dutchman could have never imagined that his charges would carry out his wishes so effectively throughout a ruthless first-half performance.
By virtue of the fact that the home fans were in 'Ole' mode within 14 minutes of kickoff, it is safe to say that Southampton enjoyed a good start - and perhaps an understatement.
Mane scored the quickest hat-trick in Premier League history to establish a 3-0 lead, before Long added two more - including a spectacular lob to complete his brace - as the hosts emphatically finally began playing like a team keen to secure Europa League qualification, having picked up just one point from a possible 12 prior to today.
While it is tempting to cite Villa's deficiencies as a big factor in the result, it would also be unfair to ignore Southampton's performance on the day. They were excellent, evoking memories of their stunning early-season form, and if Villa made errors it was partially because the hosts' high-intensity pressing forced the visitors into making them.
Aston Villa's performance
Aston Villa made the 140-mile trip to Southampton knowing that victory would see them officially win their Premier League relegation battle, but their top-flight status may just be hanging in the balance again following a farcical performance that warranted a heavy defeat.
Bizarrely, they had the first real chance of the clash as Christian Benteke fired wide from a good position. Neither manager Tim Sherwood nor Benteke himself could have known how costly that miss would prove as Southampton dominated from that point onwards.
Minutes later, Mane ran on to Pelle's flick-on to score the first of his record-breaking treble; scored in two minutes and 56 seconds. It was the second that will infuriate Sherwood, with veteran defender Vlaar culpable with a sloppy back pass before Mane rolled into an empty net. There was a degree of farce about four of the first five goals from the visitors' perspective - three of which were effectively open goals, which may tell its own story.
Right-back Alan Hutton operating at left-back did them no favours at all, with the Scot looking totally out of his depth after coming into the team to replace the injured Kieran Richardson. Sherwood perhaps could have changed things around because it was evident from early on that Hutton was a problem at left-back.
Benteke pulled one back to make it 5-1 on the stroke of half time with a brilliant header, but even then much of the noise emanated from the home fans, who ironically cheered the consolation. The remaining Villa fans, after hundreds left, saw the funny side and broke out in a chorus of "we're going to win 6-5". They were not, and Pelle finished off a fine move late on to do the Villans' goal difference no good at all.
Sherwood's post-match interview will be interesting. He is often honest, perhaps a little too much so according to some, but he may have to curb that a little in order to avoid worsening his side's already frail confidence ahead of the relegation run-in and an FA Cup final with Arsenal. He will have had 45 minutes to think of what he was is to say to the media, and publicly bashing his players could bring about negative repercussions at the worst possible time.
Sports Mole's man of the match
Sadio Mane: It was a toss-up between Mane, whose record-breaking hat-trick sent the hosts well on their way, and Long, who had a hand in four of the first give goals; scoring two, assisting one and effectively creating another by gambling where few other strikers would have after anticipating Vlaar's back pass. In the end, it has to be Mane, who not only secured the match ball but found himself playing with a real verve that has eluded him for much of 2015.
With the way in which Villa were defending, a four-goal deficit at the interval was perhaps always on the cards, but Vlaar certainly helped Southampton on their way.
The Dutchman's suicidal back pass to Given was pounced on by Long, who was upended by his fellow Irishman before Mane rolled home the second of the afternoon. At 1-0, Villa needed a bit of calm, especially from arguably their best defender, but Vlaar's error certainly contributed to this horror show.
Robert Madley had a quiet afternoon, booking Ashley Westwood and Victor Wanyama in a relatively uneventful contest. One of his linesmen did not cover himself in too much glory, though, after ruling out Pelle's opening goal for offside when replays proved otherwise.
Southampton: The Saints conclude an encouraging overall season with a visit to resurgent Manchester City, who have won their last four games, on Sunday.
Aston Villa: Sherwood's charges face already-relegated Burnley on Sunday.