Justin Rose finds the centre of the 18th fairway with his tee shot. Can he follow it in from 200 yards? He's looking anxiously after his ball. He doesn't like it. An unusual angry swipe of the club speaks volumes. His ball hits the left-edge of the green and topples off down a steep slope. Any hopes of a closing birdie are surely gone.

Brooks Koepka's ball is about three yards in front of Rose's. The American's radar is working a little better. Heart of the green and a birdie chance.

Shane Lowry looks like he's going to be hard to move. I remember him leading the WGC Bridgestone Invitational in 2015 and he properly dug in to get it done.

Again he looks good on the 15th fairway, landing on the green to leave maybe 15ft or so for birdie. JB Holmes has similar but he got lucky with a kind bounce.

Alex Bysouth
BBC Sport at Royal Portrush

Tommy Fleetwood makes it safely through the intimidating Calamity Corner.

Over to you, Shane Lowry... that sheer drop to the right of the green must look like the Grand Canyon from the tee box when you’re leading The Open.

Jordan makes a good go at a monster birdie attempt at the last, but he's a few feet short. The par is a formality and that's a two under round, but a host of spurned birdie chances may have put paid to Spieth's hopes for this year.

But then again with the weather forecast for tomorrow, if he gets ahead of the game early enough, you never know.

Image source, Reuters

Lowry stays one ahead of Fleetwood.

Image source, BBC Sport

Here's Brooks Koepka, out with the putter for his second shot on the par-four 17th after his monster 400-yard drive. There's a couple of humps and lumps to negotiate but he's judged that to almost perfection.

The ball races up over the first ridge, down and left, up and right and comes to a stop three inches from the hole. tap-in birdie.

Justin Rose's birdie putt refuses to go in the hole and he's knocking in for par.

Image source, PA Media

Golf writer Doug Ferguson seems to share the view of several reporters on Twitter regarding the tee-time change tomorrow.

It seems us onlookers want to see what happens in crazy weather but the R&A want some kind of certainty.

Bogey for Westwood on 15, three putts have done him. JB Holmes skids out of the sand on 14 but misses his 10 footer for par.

A chance for Shane Lowry to get out of here with par and open a bit of daylight to these shot droppers... he does and he jogs to the next tee... bang up for it.

Tommy Fleetwood not going away without a fight though and makes par.

Image source, Reuters

Brooks Koepka is out with the big dog on the 17th tee. It's called Purgatory and is 405 yards long. It's downhill and if you cream your driver you might just get the sort of friendly kick down the bank that the world number one has just had.

His ball careers down the slope and comes to a stop about a yard short of the green. Wow.

Justin Rose leaks his a little left but he's got a good angle of approach for his second but he doesn't give it enough oomph. A 20-foot birdie putt coming up.

Mark Chapman
BBC Sport presenter

Image source, Getty Images

JB Holmes is slower than a snail crawling through treacle at the moment!

Plenty happening, plenty happening.

Shane Lowry has one hand on the club and is deep in the rough on 14. Apparently he hit a spectator on the back. He can get a club on this though and thuds one up, short of the green. Work to do.

JB Holmes is better placed but oh no, he finds sand. Up on 15 both Tommy Fleetwood and Lee Westwood are on the green but it's looking like it will be pars rather than anything bird like.

Key moments coming up in these closing handful of holes. Lowry needs to get up and down to preserve his lead....

No-one should count their chickens tomorrow by the looks of the forecast.

Image source, BBC Sport

Now then, JB Holmes misses a par putt on 13 and that puts some heat on him now to keep pace in these closing stages.

Don't count any chickens just yet. The weather tomorrow doesn't look a bit good and anything could happen. More on that next...

The par-three 16th is 230+ yards, played entirely across a ravine. Anything short and right is dead.

Justin Rose is shortish and rightish and staying alive. His ball clings on in the greenside rough. A chip across the green sets up a simple par putt. A three always a good score on that hole.

But Rose lets his effort slip by the right edge.

Alex Bysouth
BBC Sport at Royal Portrush

The vocal chords have had a serious workout today!

They’re soothed slightly with an “ooh” from the Fleetwood followers at 14 as his birdie putt goes agonisingly close.

A quick recharge before Shane Lowry comes through before some more a capella.

This is the life. And why not when you lead The Open...

Image source, Getty Images

Lee Westwood is hunched over on the 14th green. Golf can do that to you, take the wind right out of you and force your knees to buckle like you've taken a right hand to the chin.

It's because his birdie putt from maybe 35ft hangs on the edge. Despicable behaviour by the ball. Tommy Fleetwood doesn't hunch over but there's a brief second where the air is sucked out of him as his own ball doesn't take a final break to drop in for birdie.

Pars.

And that something was a very special moment from Tony Finau, who chips in from off the side of the green. A couple of bounces then it rolls right into the middle - what a way to end your round!

Image source, Reuters

My oh my, Shane Lowry almost... almost drains a long birdie putt on 13. It flicks the edge of the cup.

Something has happened on 18, big, big roar.....