"What is that?", says Tyrrell Hatton as his approach to the 16th comes up right and woefully short of the putting surface.

It doesn't cost the Englishman though. He chips from a horrible position to 18 feet and then sinks a left-to-right putt.

While Scottie Scheffler also picks up a par, it's birdie time for Bryson DeChambeau who plays a superbly controlled second into four feet and then tidies up.

Image source, Getty Images

Shot of the day at the 15th for Tommy Fleetwood as he drills a long iron 200 yards but manages to get it to land softly on the green to about 12 feet.

Then he rolls in the birdie putt to another huge roar with a massive hospitality tent based just off the back of the green. Great place for Tommy to produce his best hole of the day.

It's back-to-back bogeys for Jon Rahm though, as he misses the green to the left and this new hole has much bigger slopes off it than the traditional greens here at Birkdale so that leaves a really tough up and down.

This hole's had some mixed reviews so far - and even in this group Fleetwood will walk off thinking it's pretty good while Rahm will hate it.

Three off the tee for Alex Smalley after going OB. Given his serene progress to this point, his head must be a little scrambled, but he finds the short stuff this time.

He still has 211 yards for his fourth...and he plays a stunner! The ball lands softly on the front of the green and rests 12 feet from the cup.

It would be a brilliant bogey all things considered if he drops this one, but he doesn't. That's a double bogey and a five-six finish for Smalley.

Lunch will taste bitter.

Jonathan Jurejko
BBC Sport golf reporter at Royal Birkdale

Fleetwood and co arrive at one of the most talked about holes on the course.

The par-three 15th is a new hole with a narrow but long green - which is a pretty intimidating sight from the tee.

The run offs on either side are steep if you’re not metronomic with your tee-shot.

Tellingly, Fleetwood is the only one of the stellar group to hit the dancefloor, with Rahm going left and Spieth going right.

Getting your ball to stick - from the tee and from the trenches if you end up there - is not going to be easy…

Andrew Murray
Former European Tour winner on BBC Radio 5 Live

For me, the 18th is one the of the great closing holes. 508 yards and it is fraught with danger. I have been down the right-hand side where Alex Smalley has been. It is not a nice place to be.

Ben Croucher
BBC Sport journalist at Royal Birkdale

Image source, Getty Images

The 18th at Royal Birkdale is an brute of a way to close out a punishing round in these conditions.

It's playing 500 yards today which, considering the firm ground, should leave most of the field with a mid iron into the green. Throw in a slight headwind and some bunkers to catch your attention and it can get in your head.

At Monday's Last Chance Qualifier, we didn't see a single birdie. Of the first 15 players to finish round one, there was just one from Henrik Stenson.

Any players chasing victory on Sunday may want to get their scoring done on the previous 17.

The warm weather has burnt away some of the rough at Birkdale, so it's not thick, juicy wet fescue that can be so dangerous in soggy Opens.

BUT that doesn't mean it's easy - as Ken Brown explains...

Another birdie chance goes begging for the world number one at the par-three 15th, albeit this time from 20 feet.

It's a more scrambling scenario for his playing partners Bryson DeChambeau and Tyrrell Hatton, who get up and down after straying right.

Image source, Getty Images

When Argentina's Mateo Pulcini holed his 18th putt, he was inspired by his compatriot Enzo Fernandez's celebration last night.

On BBC Radio 5 Live, Pulcini said: "On the 18th my caddie said: 'Make this putt and make everyone scream and do anything you want.'

"It just came from the moment. I wouldn't want to be disrespectful with an Argentina flag. It is unbelievable the treatment I am receiving here. That came from just a good putt.

"It was a great moment. I struggled all day. I am really grateful to be here. The first 10 holes were awful, and then I started to enjoy it and had some more fun."

Image source, Getty Images

The par-five 14th is the third easiest hole on the course, but Jon Rahm and Tommy Fleetwood both make a bit of a mess of it when tangling with the left rough.

Fleetwood escapes with a par but Rahm lips out with his try so he cards his first bogey of the day. Coming on what's basically a birdie hole will leave the Spaniard fuming.

Jordan Spieth at least plays it nicely as he just about gets on the green in two and ends up making his first birdie of the day to get back to two over. He'll be thinking about finishing level par now.

Graeme Storm
Two-time European Tour winner on BBC Radio 5 Live

Image source, Getty Images

Scottie Scheffler is very good from 40-to-50 feet. He holds a lot of putts from that range. Anything from 10 feet and he doesn't commit. That one was a wide for his level of play.

Image source, Getty Images

Bryson DeChambeau has made a right hash of the 14th. He'd have been looking at the par-five as an opportunity to make hay, so to speak.

Instead he drops a shot after missing the fairway and being forced to lay up. But he then takes three with his putter and it's a shot frittered away in the Birkdale breeze.

Meanwhile, Scottie Scheffler can't drop in a birdie effort from nine feet. His putter was red hot earlier. Not the case now.

Alex Smalley looks nervous.

Failing to sufficiently factor in the stiff breeze off the left on 18, his drive is blown out of bounds!

Trouble for the leader. Watch this space.

Long-range birdie putts for this trio on the par-four 16th.

Justin Rose's attempt from almost 50 feet comes to rest about a foot from the hole and he registers a par - as do Viktor Hovland and Russell Henley.

Jonathan Jurejko
BBC Sport golf reporter at Royal Birkdale

How do you know it's a dehydrating day at the Open?

When the queue for the water refill is longer than the one at the beer tent...

We talk a lot about staying out of the Birkdale bunkers, but why? Here's Ken again with the lowdown.

Ben Croucher
BBC Sport journalist at Royal Birkdale

You'd think with hard, bouncy fairways carrying the drives beyond 350 yards that the par-fives would be really accessible today but this is Birkdale remember.

Just past 2pm in the opening round and we're still waiting for our first eagle. To put that into context, we had 36 over the course of the four days back in 2017, although only 12 in 2008.

Aggression can be rewarded but miss but even the slightest margin and the bunkers, humps and hollows are waiting to gobble up stray shots.

Caution may be the better part of valour on a day like today.

Even though leader Alex Smalley failed to cash in at 17, there are a lot of birdies out there today on what has been a pretty amenable first round at Birkdale.

Having said that...

Who needs a driver?! Keeping the headcover on the chief at the par-five 17th - the easiest hole on the course today - Alex Smalley belts a low chaser with a long iron up the fairway and it runs forever, eventually coming to a rest 305 yards up there.

From 248 yards, he hoicks his second into the greenside bunker. It's a horrible distance too - 44 yards - and he chunks it, leaving himself short of the green in three.

From there, he knocks it up to four feet and rolls in the par putt. That'll feel like a bogey, though, especially after a cracking tee shot.

Matthew Hobbs
BBC Sport journalist at Royal Birkdale

Image source, Getty Images

Justin Rose arrived at Birkdale with a combined score of 11 under at the majors this season - a record bettered only by Scottie Scheffler and Sam Burns - but he opted to miss the traditional warm-up at the Scottish Open last week.

The past four Open champions finished in the top 15 at the Scottish Open before their win.