Usual penalty taker for Bristol Rovers Scott Sinclair is sent onto the pitch to replace Kamil Conteh.

It's Cambridge who are forcing the issue. Korey Smith has an effort saved and Kelland Watts goes close with a header. Can someone find a winner?

Tyler Walton has run his socks off, and has two goals to show for it.

He is replaced by Jimmy Knowles for the final nine minutes of extra-time. With half an eye on penalties? You'd expect so by this point...

Lee Mansell
Former Bristol Rovers midfielder on BBC Radio Bristol

Those Rovers players have defended so manfully, I really do hope they can see this out or do that boxer's chance get that final punch.

They have got the players to open up this Barnsley defence, they just need that one bit of quality.

Barry Cotter has a burst of pace to race past the Gas defender and set up Sam Cosgrove but, like many of Barnsley's chances, the opportunity is wasted as it's sent flying over the bar.

We're back underway - any Oldham fan booked on a train is probably keeping half an eye on the timetables...

Tyler Walton so close to a hat-trick for Stanley, a shot hits him and drops at his feet, he spins and unleashes a strike but somehow the ball is scrambled off the line by Joel Cotterill with the keeper beaten. How big is that moment?

Both teams are trying to find a winner. Cambridge's Shayne Lavery fires just wide before Callum McManaman has an effort saved at the other end.

A double change for Oldham just before that half-time whistle with Jesurun Uchegbulam and Joe Garner replacing Otis Khan and Jake Caprice.

Two forwards sent on - is Mickey Mellon trying to win it or thinking of who he needs on the field for penalties?

Dan Agyei's missed penalty is right on the stroke of half-time.

Breathe everyone, if you can.

What else can this FA Cup tie give us?

As you were at the midway point of extra-time.

Accrington took the momentum into the added period after their last-gasp equaliser but the 10 men of Swindon are not going quietly and finished the half on top.

We have 15 minutes for someone to be a hero, if not then it's the p-word.

Good work from sub Paul Glatzel paves the way for Swindon's Rosaire Longelo to get a couple of shots away but the Stanley defence are able to block both and scramble the ball clear.

Cambridge have made a change, with Emmanuel Longelo replacing Zeno Rossi.

Brett Ormerod
Former Blackpool and Preston striker on BBC Radio Lancashire

This is like both teams are resigned to a penalty shootout.

And here comes the final section of play before penalties arrive.

Can either side prevent the dreaded shoot-out?

Three extra minutes added to the first period of extra-time after that injury to Dara Costelloe.

Image source, Rex Features

Dominic Ball is fouled and it's a spot-kick for Leyton Orient.

Up steps Dan Agyei and hits his shot WIDE.

They've reached the halfway point in extra time at the Abbey Stadium and it's still level.

And that's the first half of extra-time done and dusted.

The play is slowing dramatically with some tired legs only able to muster any energy for a chance to finish the game off.

With this much fatigue going around, one goal should do the trick. That's if we get one.

He's just saved his side with a last second equaliser, now the Leyton Orient goalkeeper Josh Keeley denies Oldham's Kane Drummond as he bears down on goal.

Breathless stuff.