Norwich know they're going to have to up the tempo a bit here and they've gone close at the start of the second half.

Kenny McLean's free-kick is glanced on by Callum Doyle but it goes just wide of the post.

A positive start from the hosts.

Danny Hall
Sheffield Star journalist on BBC Radio Sheffield

Sheffield United look rattled by this Portsmouth display.

They are more than giving a game.

Simon Lappin
Former Norwich midfielder on BBC Radio Norfolk

Norwich need to get the ball out wide because Derby are so compact.

They have frustrated Norwich so far.

Pompey have the ball in the back of the net for the second time today but it wont count.

Colby Bishop's effort is ruled out for offside.

Image source, Rex Features

We're getting back under way in the day's remaining two Championship games.

Danny Hall
Sheffield Star journalist on BBC Radio Sheffield

Image source, Rex Features

So many times Josh Murphy seemed to be getting that yard of space without even really earning it.

It's been very basic fundamental stuff and United have not been able to deal with that.

You think when they scored they'd go on but Portsmouth said we're in this with the goal and that seemed to have caused chaos in the United defence.

A strange half and I'm sure Chris Wilder will have words to get that solidarity in the second half.

Just like at Carrow Road, it's goalless at Deepdale between Preston and Wycombe and at St Mary's between Southampton and Burnley.

When will the Clarets concede a goal? It's been almost a month since Reading scored against them in the third round and they have shut out every opponent since.

There's more excitement at Stoke, who have pulled one back after going two goals down against Cardiff.

But Coventry is where the action is at - the Sky Blues trail Premier League Ipswich by three goals to one.

You can follow the FA Cup fourth round action here.

Image source, PA Media

Honours even at the break between the promotion chasers and strugglers.

The away side missed a great early chance to take the lead when Callum Lang fired over with the goal at his mercy.

Gus Hamer then put the home side in front with a cool finish but the visitors hit straight back through Connor Ogilvie's low finish.

Since then Josh Murphy has hit the bar for the strugglers and Ogilvie has missed a sitter too.

A draw does move United back up to second but they'll want all three.

Big second half coming up in this one.

Image source, PA Media

The referee brings and end to a half that will not live long in the memory.

Two disallowed goals - one at each end - feel like a distant memory as it felt like we were going to be set up for an absolute cracker.

Derby striker Lars-Jorgen Salvesen looked to be behind the ball when he finished off a good Rams move but the flag was raised nontheless.

Lewis Dobbin was then flagged offside himself as he scored at the other end moments later.

But since then, it's been largely forgettable.

Harry Clarke nearly puts the home side back in front just before the break but his effort is turned behind by Pompey keeper Nicolas Schmid.

Some game this.

One added minute at Carrow Road.

Danny Hall
Sheffield Star journalist on BBC Radio Sheffield

Connor Ogilvie has absolutely ballooned that and he kicks the post in frustration.

But again it's so simple as Michael Cooper screams at his defenders.

He should score, you couldn't ask for a better chance to score.

Portsmouth will really feel they should be leading this one.

They had the better chances before the hosts took the lead and since they equalised they have hit the crossbar through Josh Murphy and now goalscorer Connor Ogilvie puts the ball over from close range from a Murphy centre.

Simon Lappin
Former Norwich midfielder on BBC Radio Norfolk

Neither goalkeeper has been tested.

Norwich been here on many occasions before and the most calm of them all are those on the pitch.

Marcelino Nunez escapes a booking for a challenge on Derby's Ebou Adams.

Some frustration creeping in at Carrow Road. Norwich are the league's second top scorers but they're not having things their way at the moment.

This new-look Derby side are defending deeply and resolutely in their determination to avoid an eighth straight defeat.

The away side are having a real go here!

Josh Murphy cuts in off the left and hits a fine curled effort that thunders against the crossbar.

Eric Steele
Former Derby and Man Utd goalkeeper on BBC Radio Derby

You sense the frustration from Norwich. They like to play neat touches in their football and Derby have frustrated them.

Derby have done well on the break.

Nathaniel Mendez-Laing has done well so far.

A quick round-up of what's going on with the Championship sides playing in the FA Cup fourth round today.

Coventry and Ipswich are level 1-1 while Cardiff have a 2-0 lead at Stoke City.

Preston v Wycombe and Southampton v Burnley are goalless.

And with that, let's get back to the Championship.

Portsmouth have lost their previous six games on the road and are without a win at Bramall Lane since 1955.

They're giving as good as they're getting so far today though and are deservedly level.

Derby midfielder Ebou Adams picks up a yellow card for a sliding challenge in the middle of the park.

The Rams look really up for this one.