That is all from me.
A reminder you can follow all the reaction to today's games - including this one - by heading over here.
One last boom into the box?
There is no time!
West Ham win for the first time since 24 October!
Deep cross... SAFE!
Adrian claims it and surely from here West Ham can breathe?
This is so poor from Gaston Ramirez. Juanmi bursts through the West Ham line, tees up Ramirez for a cross but it is wayward to say the least.
Are the Hammers going to see this one through?
Virgil van Dijk with a chance - the ball falls to him in the box but it's stabbed wide!
Four minutes of added time...
Michail Antonio can seal this!
He's running away from everyone, but blazes madly wide of the Southampton net at the vital moment.
Will the Hammers regret that?
Last change for West Ham, a defensive one as Pedro Obiang comes on for Enner Valencia.
Southampton launching it forward, James Collins booming it away on his head.
He's been a massive presence for the Hammers.
What a return from injury this is turning out to be!
Andy Carroll nods home from close range after Michail Antonio's header hits the underside of the bar and comes back to him.
Just over 10 minutes to play, can we call him a matchwinner?
This is a big last 15 minutes now.
Is there a winner out there? West Ham seem to have gone slightly off the boil after that leveller...
Dusan Tadic off for Gaston Ramirez and Juanmi on for Sadio Mane for Southampton.
Fresh legs up top. Is Ronald Koeman going for this?
Cuco Martina off and Maya Yoshida on for Southampton.
This is not the ideal time to be coming on as a defender. West Ham have got their tails up big time.
They're looking for Andy Carroll every time now. Can the big man get the winner on his return?
What. On. Earth?
Michail Antonio cannot believe his luck. Running in from the left he trips over in the box - the fans want a penalty, but soon forget all about it as Southampton's clearance booms off the West Ham winger and into the net!
Bizarre doesn't come close!
Overload for Southampton, and Steven Davis goes for the spectacular...
But he is not Davor Suker chipping Peter Schmeichel in Euro 96. West Ham keeper Adrian easily collects.
Might a ball through to Shane Long have been the better option? West Ham were exposed.
Had to be.
Michail Antonio had broken clear down the right wing, and all Ryan Bertrand could do was trip him down from behind. Yellow, but the free-kick is cleared.
Unlucky Carl Jenkinson
Tearing down the right wing (again) he's almost running too quickly for his own good trying to evade the dogged Shane Long.
He ends up toeing the ball rather meekly towards the Southampton net, when for a moment it looked like he'd broken free.
Just half an hour to play. It's all got a bit cagey.
West Ham have shown a lot more of what they can do in this second half so far though. Can they raise it another notch?
Or are Southampton going to cruise to another win?
Another booking. James Tomkins collects one for a handball that stops Dusan Tadic in his tracks.
We have our first sighting of Andy Carroll in his natural element - tracking on to that hanging high ball lofted in from the flank.
He connects and directs it downwards but there's not enough power. Easily collected.
Oriol Romeu doesn't look the type to be too abashed at picking up a booking and he's got one here.
A cynical chop to stop West Ham picking up the loose ball to counter. That's his fifth of the season and he'll miss the next match.
Bad news for Dusan Tadic - that opening goal's been taken away from him...
Cuco Martina goes into the book - he hauled down Enner Valencia. Bit of a silly challenge that, Valencia wasn't really going anywhere.
Another little tactical switch to tell you about - Carl Jenkinson is now at right-back, with James Tomkins going to the left.
Jenkinson is already finding loads of space down the right wing. This switch could be a fruitful one in time. West Ham are certainly looking much improved...
James Collins deserves a goal just for his defensive work in that first half and he nearly has one here - his header cleared off the line!
But oh my, Andy Carroll. He booms one over the bar from the edge of the six-yard box as the ball comes back in.
Not the return he will have been dreaming about...
Two changes to tell you about.
Andy Carroll is on, Mauro Zarate the man coming off.
And Manuel Lanzini also makes his return from injury - he comes on for Alex Song. Two pretty attacking moves from Slaven Bilic.
Will it pay off?
We are back under way.
What next for Slaven Bilic and company then?
Striker Andy Carroll is back, on the bench, and warming up as we speak...
I honestly can't remember a decent West Ham chance in this half. There just hasn't been one.
A very disappointing showing from the home side.
One minute added on.
But only Southampton look like scoring right now.
Make that three chances as Dusan Tadic fires straight at Adrian when well-placed outside the box.
Two very good chances for Southampton to double their lead before the break.
Jose Fonte's header from a corner is clawed away by Adrian, before Sadio Mane can't get a clean shot away when played in behind.
This is not looking good for the Hammers...
Under five to go before the break.
Southampton have had all the territory...
James Collins is having a brilliant game though.
He makes another great clearance from a Saints free-kick that threatened to swirl its way towards danger at the back post. Virgil van Dijk was ready to pounce on it.
Poor from Mauro Zarate. He gives the ball away to Steven Davis in midfield before chopping the Southampton man down in frustration. It was a lazy trip.
Slaven Bilic will be wanting much more than this...
Steven Davis with a turn and run on goal before firing just wide of the far post. Adrian was gone. Stricken is the word.
A word of sympathy for James Tomkins, who's playing with a military-grade shiner today.
If I can find any pictures I'll dig them out, but it really is a massively bruised eye.
This first half seems to have flown by. Just 15 minutes left for West Ham to get back into this before half-time.
Some clever keep-ball from the hosts and signs Southampton are dropping deep, but this move comes to naught as Mauro Zarate's low cross is easily gathered.