Inexplicable mistakes from Joe Hart and Gareth Barry dealt Manchester City's Premier League title hopes a potentially decisive blow as Southampton secured their first win under Mauricio Pochettino in style.
City goalkeeper Hart admitted in the build-up that anything but victory at St Mary's would all but end any their hopes of retaining the title, with leaders Manchester United already boasting a nine-point cushion.
Roberto Mancini's side simply did not look like a side in need of a victory tonight, conceding after just seven minutes when Jason Puncheon slotted home.

Dejection: Manchester City's title hopes are hanging by a thread after defeat at Southampton

Match facts

Southampton: Boruc, Clyne, Yoshida, Hooiveld, Fox (Richardson 71), Cork, Schneiderlin, Steven Davis (Ward-Prowse 80), Puncheon (Lallana 61), Rodriguez, Lambert.
Subs not used: Kelvin Davis, Forren, Lee, Chaplow.
Booked: Lambert.
Goals: Puncheon 7, Davis 22, Barry (og) 48.
Man City: Hart, Zabaleta, Lescott (Kolarov 66), Javi Garcia, Clichy, Nasri (Milner 55), Yaya Toure, Barry, Silva (Maicon 73), Aguero, Dzeko.
Subs not used: Pantilimon, Sinclair, Rodwell, Yaya Toure.
Booked: Clichy, Yaya Toure.
Goals: Dzeko 39.
Att: 31,738
Referee: Martin Atkinson (W Yorkshire)

The latest Premier League table, results and fixtures

Hart could have possibly done better with the shot that led to the opener, but there was no doubting his culpability for Southampton's second.
Excellent team interplay put through Rickie Lambert, whose fierce drive squirmed through the England international's grasp, allowing Steven Davis to bundle home.
Edin Dzeko reduced the deficit as half-time approached, although a two-goal lead could have been restored on the stroke of half-time had referee Martin Atkinson not waved away Jay Rodriguez's penalty appeals.
That was soon forgotten, though, as Barry passed into his own goal unchallenged to put Saints on course for a first win since Pochettino replaced Nigel Adkins at the helm.
On the opening day of the season the newly-promoted side were valiant in a 3-2 defeat at the Etihad Stadium.
It was a similarly end-to-end encounter this evening, with Saints dominating the proceedings early on and netting a seventh-minute opener.
After Barry was dispossessed, Puncheon burst down the right flank and played through the unmarked Rodriguez. Hart managed to deny the winger but the ball fell kindly for Puncheon, who slotted home calmly in front of the Northam End.

Dream start: Jason Puncheon gave Southampton the lead in the seventh minute

City were struggling to deal with Southampton's attacking intent in an opening 15 minutes in which a tame Sergio Aguero effort was all they had to show for their efforts.
They eventually began to settle but were soon rocked by a second Southampton goal in the 22nd minute.
Lambert collected the ball on the right and played a neat one-two with Puncheon, before cutting back and firing a shot that Hart let slip through from his midriff, allowing Davis to poke home.
Saints fans ironically bellowed 'England No.1' after the gaffe, before directing their attention at referee Atkinson.

Scorer: Puncheon celebrated his goal with some unusual moves

First they took umbrage with his decision to book Lambert for hauling back Joleon Lescott, before he then awarded a foul on the edge of the box after Dzeko took a tumble.
Rodriguez saw a right-foot effort go just inches wide of Hart's far post as the home side pressed for a third, with Nathaniel Clyne seeing a strike deflect behind.
Pablo Zabaleta floated ball to the back post just evaded Aguero as City looked for a goal, which came six minutes before half-time.

Error: Joe Hart let the ball go through his legs and Steven Davis pounced to double Southampton's lead

Joe Hart of Manchester City dives in vain

The Bosnian striker got himself in the way of terrible Saints corner, before bursting up the field and tucking home a Zabaleta cross.
It was harsh on the hosts, who felt hard done by in stoppage-time when Rodriguez was brought to ground in the area by Yaya Toure, captaining the side on his return from the African Nations Cup.
Atkinson awarded a corner instead of a spot-kick much to the home fans' frustrations - but they were celebrating soon after the restart.

Oh dear, Roberto: City boss Mancini looking gutted

Happy: Mauricio Pochettino earned his first win

Game on: Edin Dzeko scored just before half-time to reduce Southampton's lead to 2-1

After Puncheon hammered over moments into the second half, the winger could then not quite latch onto a Lambert pullback, which Barry inexplicably passed into his own goal.
Gael Clichy was booked soon after as City's frustrations became evident, with Saints pushing for a fourth.
The visitors were having to defend with all they had and hope for a chance on the counter, with Artur Boruc reacting well to palm away an Aguero strike wide when they did voyage forward.

Calamity: Garth Barry scored a disastrous own-goal at the start of the second half

James Milner, on moments earlier for Samir Nasri, shot wide from the resulting corner but City were soon back on the defence.
Toure was booked for a foul on substitute Adam Lallana soon after, before Fox limped off to be replaced by Frazer Richardson.

Laughable: Davis celebrates Barry's own-goal which restored Southampton's two-goal lead

Aleksandar Kolarov and Maicon were City's final introductions, with the latter soon denied from close range by Boruc.
James Ward-Prowse replaced Davis for what a nervy final 10 minutes in which City were kept at bay, meaning United could go 12 points clear at the top should they beat Everton tomorrow.

Gap: City's title rivals Manchester United can go 12 points clear with a win against Everton on Sunday

Chelsea 4 Wigan 1

Back with a win: Eden Hazard (centre) scored on his return to action to halt Chelsea's four match winless run

Cool: Hazard's neat finish made it 2-1

Closing in: Frank Lampard (left) scored his 198th goal for Chelsea leaving him just four short of Bobby Tambling's club record

Maloney crossed from the right and Azpilicueta had to head behind, with James McArthur lurking at the back post.

Oscar curled over as the first half came to a close and Lampard had an effort blocked on the resumption.

Sunderland 0 Arsenal 1.

Santi's come to town: Arsenal beat Sunderland thanks to Santi Cazorla's first-half strike

SWANSEA YAICHAPA QPR,MICHU ATISHA

Swansea 4 QPR 1

New look: Michu of Swansea celebrates scoring the opening goal

Hot shot: Angel Rangel scores Swansea's second goal

Early strike: Miguel Michu seizes on sloppy backpass to open the scoring

STOKE CITY WAICHAPA READING

Stoke 2 Reading 1

Towering: Robert Huth rose highest at the far post to give Stoke the lead

They remain 17th in the table, two points clear of the relegation zone, while Stoke stay 10th.Adrian Mariappa pulled one back with a header two minutes later, but the Royals -