Preston sub Chris Humphrey uses his pace to great effect, racing down the right touchline and putting in a cross that doesn't quite reach Jermaine Beckford in the centre. It's a corner, though, which Joe Garner heads well over.

Jamie Hoyland
Ex-Bury and Burnley midfielder, BBC Radio 5 live sports extra

"Preston have looked comfortable. I know there was that chance in the first half and Sam Johnstone has pulled off a good save, but other than that they've looked comfortable and got the goals at the right times."

Chesterfield winger Gary Roberts goes down in pain and signals to the bench to say he's unable to continue. Maybe a kick on the knee? Anyway, his afternoon is over, and Dan Gardner is on for the final nine minutes and stoppage time.

Another Chesterfield corner comes to nothing, as Armand Gnanduillet heads tamely and well wide.

When you're trailing in a cup tie with 15 minutes left, the last thing you want to see is a lightning quick winger coming off the bench. Chris Humphrey is on for Preston in place of Calum Woods.

Image source, Getty Images

Chesterfield's Jimmy Ryan tries one from long range and his shot fizzes just wide. From the next attack, Jay O'Shea hits the post at the end of a mazy run. You get the feeling it's just not going to be Chesterfield's day.

Nathan Middleton
BBC Sport at Deepdale

"There's a party atmosphere inside Deepdale now as Preston fans go through various routines of Wembley chants, as well as a few renditions of 'we are going up'.

"In contrast, it's much quieter from the away faithful, who've spent the majority of the time since Joe Garner's penalty sat down not making too much noise."

Preston's second change sees Scott Laird - a scorer in their FA Cup defeat by Manchester United earlier this season - come on for young midfielder Daniel Johnson. The experienced Laird will add another calm head to proceedings as North End look to see this game out without alarm.

Chesterfield have come back from a similar position to this at Deepdale already this season. The Spireites trailed 3-0 in their league meeting in September but fought back to draw 3-3 with an Eoin Doyle hat-trick. How they must wish Doyle was in their squad today.

That's Daniel Jones' last action, as the Chesterfield left-back is replaced by the more attacking Gboly Ariyibi.

It's Chesterfield's second change - striker Armand Gnanduillet came on for Ollie Banks just after Preston's second goal.

The Preston fans are jumping up and down now. They know they're just one more win away from a place in the Championship.

On the field, North End captain Tom Clarke has been booked for a tackle on Daniel Jones.

Image source, Getty Images

Joe Garner has happy memories of League One play-off semi-finals at Deepdale. Remember this wonder volley against Rotherham last season?

Now he's scored the penalty that has, more or less, confirmed North End's place at Wembley on 24 May.

Image source, Getty Images

As a goalkeeper in these games, you can either be a hero or a villain. Joe Murphy, signed yesterday by Chesterfield, is the villain here as he rushes from his goal line and brings down Daniel Johnson with the Preston man going well away from goal. A cheap penalty, clinically converted by Joe Garner.

Barring a second-half collapse, Preston are heading to Wembley.

Penalty for Preston...

Image source, Getty Images

Chesterfield have had 75% possession so far in this second half but have yet to seriously test Sam Johnstone in the Preston goal. They could do with a breakthrough, and quickly.

A dangerous cross from Daniel Jones, who's galloped down the Chesterfield left time and again today, earns the visitors a corner. Gary Roberts drills it in and finds Ian Evatt, but the big defender heads straight at Sam Johnstone from 18 yards.

And here is that substitution, as Paul Gallagher is helped from the field and replaced by youngster Alan Browne.

Preston are preparing a substitution as Paul Gallagher is struggling with a knock.

Just the start Chesterfield wanted - a sustained spell of pressure inside Preston territory and the hosts are forced to concede a corner. It's cleared to safety but Chesterfield retain possession.

Chesterfield kick off the second half. They need at least two goals in this half to keep their dreams of back-to-back promotions alive.