That's back-to-back birdies for Rory McIlroy as he makes no mistake knocking his putt in after that wonderful approach.

Three under after six and the McIlroy fans at St Andrews are starting to get very excited.

Viktor Hovland finds the par-five fifth green with two hearty blows, but he's over 100 feet from the pin - that's the Old Course for ya.

The Norwegian's first putt is poorly judged, though, and he's lucky to hold the front of the green! His birdie effort coming back sneaks off to the left. Par.

Shane Lowry, also putting from another postcode for eagle, makes a much better fist of it and that's a much-needed birdie for the Irishman.

It's a birdie for Justin Thomas, too. He's playing error-free golf but his outfit is generating more discussion than his game at the moment.

Stunning approach from McIlroy on six and he'll have another birdie try, while Morikawa comes up badly short, which is a huge error for an iron player like him, and he's got serious work to do for par.

Peter Scrivener
BBC Sport at St Andrews

If you're unfamiliar with the Old Course layout, it's basically seven holes straight out from the town of St Andrews towards the Eden estuary and then the eighth, ninth, 10th and 11th are in clockwise loop - with the short 11th playing across the seventh - and leading to the 12th, which starts the run back to the town.

Arguably the best place to watch some golf is in the stand by the 10th green which affords great views around the holes in the loop.

There are seven shared greens - with the hole numbers adding up to 18, so 2&16, 3&15, 4&14, 5&13, 6&12, 7&11 and 8&10 and they are enormous.

Only holes one, nine, 17 and 18 are solitary greens.

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

If you look at Rory's game over the first five holes - you might not have his irons where he wants them to be, but his putter is spot on.

-6 Cameron Young (11)

-4 Barclay Brown (68)

-4 Jooyhung Kim (14)

-4 Cameron Smith (12)

-4 Brad Kennedy (7)

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Rory McIlroy knocks in the birdie putt easily enough and it's a very solid and impressive start so far.

Xander Schauffele also picks up a birdie here and Collin Morikawa follows him to get back to level par.

Alex Bysouth
BBC Sport at St Andrews

A lady, who I assume must be part of Team Daly, leans over the ropes and hands him a couple of diet cokes en route to the 14th tee. A young lad then offers up a beer (it was really just a fizzy drink…) and the American respectfully declines.

Little John, his son and caddie, is getting almost as much recognition as his dad - a spectator calls out to him and the youngster offers a wave in response.

And Young lands the birdie put on 11 to go six under and lead by two shots from a four-man group on four under.

It's a first Open Championship for Young but he's taken to it like a duck to water so far.

Lovely touch from McIlroy - after he comes up short with his second he uses the up-slope to send his chip high into the St Andrews sky and it lands as light as a feather to set-up a big birdie chance.

Cameron Young is the solo leader of The Open after he makes a birdie on nine to get to five under.

The big-hitting American has used his power perfectly in a flawless front nine of 31, and after a par on 10 he's hit a stunner on the par-three 11th and has a great chance to pick up another shot.

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

To combat course congestion - you can take breaks on the driving range - because you are going to get these breaks in play.

It comes down to personalities - Rory likes a chat but you might get players that don't like to chat and just want to get on with things

Rory McIlroy finally tees off on the par-five fifth after a bit of a wait - play is just starting to slow up a bit as usually happens at St Andrews with shared greens and some narrow fairways that also cross over each other.

Robert MacIntyre looks dialled-in on the greens and he drains a lovely 30-footer at the 10th to move to three-under!

Promising stuff from the world's top-ranked Scot.

Time for another delve into our Open archives and although this is of a Jack Nicklaus victory - this Open was all about poor old Doug Sanders and one of the most famous missed putts in golfing history...

Now then, Viktor Hovland finds himself in a spot of bother at the fourth. His ball is up against the left-hand side of one of the treacherous pot bunkers off the back of the green.

He tests out a few different stances and, following a lengthy discussion with his caddie, eventually opts for the one-foot-in-one-foot-out approach and thumps it out left into the rough, from where he gets up and down for an adventurous bogey.

Shane Lowry was in a better spot in that same greenside trap but plays a poor one and misses the putt. Three over now. It's surprising to see Lowry struggling.

Alex Bysouth
BBC Sport at St Andrews

John Daly makes his booming drive count with a birdie at 12, he had the bonus of following Bryson’s line after the American overcooked it a touch, three-putting for par after nailing the green off the tee.

I still can’t get over Daly’s trousers. The skulls and pink roses combo. His glove drops from his pocket on the walk to the 13th tee. A helpful steward hands it back and Daly looks him deep in the eyes, before delivering a considered “thank you”.

That's a brilliant opening round from Barclay Brown, but he'll be a tad disappointed not to have birdied the 18th after taking three from the left edge of the green.

But it's still a hugely impressive start from the 21-year-old Englishman, and he'll definitely enjoy his lunch.

Image source, Getty Images