Scott Twine's five Championship goals matches his tally from last season
Scott Twine scored two goals in quick succession for Bristol City to beat Southampton and move up to fourth in the Championship.
Adam Armstrong chipped Radek Vitek in the Bristol City goal to open the scoring for Saints, but less than three minutes later Anis Mehmeti struck the hosts level.
Twine then found the net twice in seven second-half minutes, reacting quickest to tap the ball in after Zak Vyner's deflected shot ricocheted off the post, before leaping on a sloppy Saints pass to sprint half the pitch and strike the ball beyond Alex McCarthy.
The defeat mounts pressure on Saints manager Will Still as his side drop a place to 17th in the table and now have just two wins in 11 league games.
After an uninspiring 0-0 draw at home to Swansea on Saturday, Southampton's travelling fans left Ashton Gate before full-time in their numbers as their side fell to a fourth league loss of the season and continue to languish closer to the bottom three than the top six.
Saints dominated possession early, as Cameron Archer twice got in behind and saw one half-attempt go over the bar.
Adam Armstrong was then played into space down the right but his strike did not trouble City keeper Vitek who had the time to get down low and keep his effort out.
The second time he did not miss though as Shea Charles threaded a pass neatly through the middle and the experienced striker rolled right to his feet between two defenders and he had the time to look up, pick his spot and chip the ball over Vitek.
Bristol City had created nothing to majorly trouble Southampton's goal when less than three minutes later Mehmeti drew them level from nowhere.
From inside his own half, Rob Dickie's long pass bobbled past Nathan Wood as he tried to intercept and found Mehmeti, who ran into the box and slotted the ball into the far corner for his fifth goal this campaign.
Neto Borges headed wide and Mark Sykes also missed the target as City pressed for a second but it was Southampton who should have gone 2-1 up.
Adam Armstrong teed up Archer who beat the offside flag and had time and space to take a shot, but Manchester United loanee Vitek impressively stood tall and strong to keep the score all square at half-time.
Scott Twine spent time in the Southampton academy as a schoolboy
Saints came out just as determined as Leo Scienza hit the crossbar and Archer missed another opportunity, heading over the bar from a few yards out.
Yet City continued to look equally threatening as Mehmeti fired a rocket of a shot narrowly wide before Twine put them in front on 56 minutes.
Vyner's shot deflected off Sinclair Armstrong onto the woodwork and seemed to confuse the Southampton defence, who stood still waiting for an offside flag that was not coming as Twine capitalised to clip in the rebound.
His second goal was all his own doing, however, as the midfielder leapt on a weak pass from Caspar Jander on halfway and sprinted towards McCarthy, holding his composure and lifting the ball over his head to make it 3-1.
Saints tried to rally what they could during the final 25 minutes but looked out of ideas as Bristol City's defence held firm for their second home win this season.
'We give ourselves a mountain to climb' - Still
Bristol City head coach Gerhard Struber told BBC Radio Bristol:
"We are happy, we dealt with a big opponent, we are on a really good level.
"We struggled a little bit in the first half especially in the first 30 minutes, we were not always on the same page in the way we press. It was really good that we bounced back with Anis Mehmeti, showed them how difficult it is against us.
"The second half we changed the pressing line and waited for the right moment to come in transitions, we killed them today over this phase and I'm very happy with how the boys did it, how smart they dealt with them.
"We spoke with the boys that we should be at home on the same balance like [we are] away and today we had the same energy, the smart pressing and were clean enough to score."
Struber: 'Today we had the right energy'
Southampton manager Will Still told BBC Radio Solent:
"We've been totally dominant and in control for the first half again, scored a great goal and created three if not four really big opportunities to kill the game off and win it.
"[We] come back out after the break, played really well for 10, 15 minutes, hit the crossbar, somehow missed from a couple of yards out.
"And to make things as worse as they can get a shot that's going about six yards away from goal and gets deflected and hits the post, somehow falls into their feet and we concede.
"The last one you're chasing the game again, trying to look forwards, pass it sideways and they've not had to do very much to win the game of football and we give ourselves a mountain to climb every single time.
"It's just not going our way. You can talk about tactics, intensity, whatever, if you watch the first half as a whole, if we don't make a mistake they've literally almost not come over the halfway line."
Will Still: 'They've not had to do much to win'
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