Huddersfield boss Darren Moore has unsurprisingly made two changes at the break.

Thomas Edwards and Brahima Diarra are replaced by Matt Pearson and Ben Jackson.

Leeds remain unchanged.

A diving header from Southampton's Adam Armstrong goes just wide.

The ball was whipped in, medium height, by Kyle Walker-Peters (who has been brilliant down that right side for Saints today) and Armstrong threw himself at the ball, good connection, just slightly off target.

You don't see enough diving headers these days.

The rain is coming down at Elland Road.

Will we see a further torrent of goals from the host?

Corner Birmingham.

The ball swings into the box but it's headed away by Saints and lands for a Blues defender on the edge of the area who swipes wildly and misses the shot.

Cleared.

Nice one touch passes between Southampton's Stuart Armstrong and Adam Armstrong on the far side corner of the Birmingham box.

The Blues defenders don't shut them down and Adam Armstrong has a shot but he doesn't quite catch the ball cleanly and it rolls to the feet of John Ruddy in goal.

A bright start from the home side.

Before today's Yorkshire derby, Crysencio Summerville already boasted an impressive home record for Leeds.

From nine home league starts before today, Summerville had been involved in six goals (three goals, three assists), scoring twice and assisting twice in five home starts this season.

Add today's double and you have a real Elland Road love affair going on.

Back underway at St Mary's.

No changes for either side.

Can Birmingham get back into this one?

Matt Glennon
Former Huddersfield keeper on BBC Radio Leeds

Darren Moore has got a big challenge ahead of him in the changing room in the next 15 minutes.

What is he going to say? What is he going to change? How is the second half going to go?

Daniel Herbert: From a Saints fan. Eustace was doing a brilliant job. Just because you're an England legend, doesn't mean you'll be a great manager. It shows everything wrong with English football. Reminds me of Adkins sacking from Saints when we first got back to the Prem. Disgraceful!

Two goals each from Dan James and Crysencio Summerville has Leeds United in dreamland right now.

This is very much a nightmare for Huddersfield.

Image source, Rex Features

Matt Glennon
Former Huddersfield keeper on BBC Radio Leeds

I have never seen so much space open up on one side of a pitch. It's time to get bodies around him and block the strike but he drops a shoulder and all the players go the same way.

I feel for Lee Nicholls because he's had no chance and no protection infront of him.

There is only one word for it... it's a disaster.

RICH: Time to bring Patrick Bamford on for the second half? Give him a good run out at 3-0 up and put Wednesday behind him....?

Image source, Getty Images

Southampton are well in charge of this one at St Mary's and look very comfortable.

Birmingham haven't offered much in reply to Saints two goals.

Dreamland for Saints boss Russell Martin. A nightmare so far for new Blues boss Wayne Rooney as he heads towards a third straight loss.

Southampton's Adam Armstrong is fed the ball following a beautiful little flick-on and runs on to it on the farside edge of the Birmingham box.

He tries poking a shot past Blues keeper John Ruddy who comes off his line and makes himself big and manages to deflect the shot wide.

Good save.

Emmanuel Longelo goes into the book for kicking the ball away following a challenge (scrap) with Southampton's second goalscorer Carlos Alcaraz.

Lee Nicholls comes with a vital intervention to limit the first-half damage.

He first denies Crysencio Summerville before Dan James almost completes his hat-trick. Those were two huge chances for Leeds.

Less than five minutes of normal time in this first half remaining.

Birmingham are trying to reclaim the ball Southampton's half.

Can the visitors get one back before the break?

It's not looking likely ... but anything could happen right?

Southampton have dominated this first half.

They've had 76% possession compared to Birmingham's 24% so far.

And Saints have strung together 340 passes to the Blues' 106.

Huddersfield's Sorba Thomas is the second to go into referee James Bell's book.

There is no hesitation as the yellow card comes out for Thomas' foul on Sam Byram.

It's been a half to forget for Darren Moore's side.

Image source, Getty Images