George O'Neill
BBC Sport Scotland at The Renaissance Club

It’s seriously warm now in East Lothian, at least it is for a pasty bloke from Yorkshire.

Rory McIlroy’s putter stays cold though as his long birdie effort comes up short.

Xander Schauffele makes a tricky, sloping putt look easy, leaving a simple tap-in for his par, before Victor Hovland goes one better, draining a long birdie effort.

McIlroy holes his testing par putt to settle any nerves.

A purposeful stride for McIlroy as he set off on his mission to win his second Scottish Open title in three years.

All three walk off the first with a par.

A nerve settler.

JJ Spaun's approach shot shows why he is the US Open champ. A sensational second is stuck to roughly eight feet.

Tommy Fleetwood takes the same line, but he can't get any spin on it - he was downwind and not too far away in fairness - and it skites through the green.

Scotland's Connor Syme joins him on the back of the putting surface.

George O'Neill
BBC Sport Scotland at The Renaissance Club

A big mistake from Victor Hovland as the Nowegian clips a tree with his second shot and comes up well short of the green.

He recovers superbly though with a wedge to six inches that he taps in for par.

Xander Schauffele tries to take the low route under said tree, but runs through the back of the green.

The American gets up and down superbly for par, but McIlroy leaves a dreadful putt well short of the hole and subsequently makes bogey.

Nice to see it’s not just hackers like me that three putt.

Scotland's Connor Syme is getting under way.

Alongside him is US Open champion JJ Spaun and England's Tommy Fleetwood, who is teeing it up for the first time since his gut-wrenching loss at the Travelers Championship.

A couple of late dropped shots across this trio, and one of this morning's marquee groups finishes for the day.

All sitting in decent shape ahead of Friday.

Image source, Getty Images

George O'Neill
BBC Sport Scotland at The Renaissance Club

Huge cheers for Rory McIlroy on the first tee and the Masters champion smashes driver into the right rough.

A slight mishap from the tournament announcer, who introduces Open champion ‘Xander Hovland’ before quickly correcting himself.

It is, of course, Victor Hovland and Xander Schauffele playing with McIlroy.

Image source, Getty Images

Here's the next superstar trio - Rory McIlroy, Viktor Hovland and Xander Schauffele.

Decent tee shots from all three, and the Europeans share a laugh as they stride down the fairway.

I mentioned Bud Cauley just a moment ago - he's now -4 through six. Talk about a fast start!

Quite a lot of those near the top of the leaderboard have now finished up, but there's a few recent starters who have fired out the blocks.

American Bud Cauley and South African Jacques Kruyswijk are playing partners, and they're both three-under through five having started on the 10th.

A dream start, but can they keep it up for the whole 18?

New Zealand's Ryan Fox, a two-time PGA Tour winner this year at the Canadian Open and the Myrtle Beach Classic, is off.

Alongside him is Aldrich Potgieter, who is currently ranked first for driving distance on the PGA Tour at an average of 328.4 yards.

The 20-year-old South African has also won stateside this year, his title coming at the Rocket Classic recently.

Justin Rose - who needs no introduction - is also in this group, and he can expect to be hitting first most of the afternoon, given the power of the other two.

Certainly an interesting trio to keep an eye on.

Group 21 - the headliners - have finished up.

Scottie Scheffler, who looked a little uncomfortable at times and was stretching his back, finishes with a three-under 67.

Adam Scott has been less fortunate, he's a one-under 69.

As for the defending champion, it was a two-under 68 after a lovely approach on the eighth that led to a birdie. Keep an eye out for that.

Ludvig Aberg has a great chance at birdie, from all of four feet on the eighth hole... and he pushes it right. A bad miss, and not the first that opportunity that has passed him by.

He's -3 through 17 but he'll know it could be more.

Meanwhile, Jake Knapp knocks in a par putt to confirm his score of 64 for the day and a share of the clubhouse lead.

Martin Watt
BBC Sport Scotland at the Renaissance Club

No closing birdie for Sepp Straka on the par-three ninth but a fine round of 64 for a share of the clubhouse lead.

Justin Thomas' dad Mike is among the fans here and shows his appreciation as his son puts it close from off the green to ensure par for a one-under 69.

Image source, Getty Images

Approaching the end of the round for the superstar group today.

Adam Scott tries a putt from 43 feet. It looks good... but lips out! He has the good grace to grin, but that's a sickener.

Up next is the home favourite Bob MacIntyre with a birdie chance, and he pours it in! A little fist pump of celebration.

Scottie Scheffler is just looking at par, and it's straightforward for him. Onto the ninth - the last of their day.

T1. Nico Echavarria -6 (64)

T1. Jake Knapp -6 (17)

T1. Sepp Straka -6 (17)

T4. Marcel Siem -5 (65)

T4. Calum Hill -5 (65)

T6. Wyndham Clark -4 (66)

T6. Elvis Smylie -4 (16)

T6. Ludvig Aberg -4 (15)

T6. Collin Morikawa -4 (15)

T6. Alejandro Del Rey -4 (14)

Another new name enters the leaderboard, and it's a good'un - Elvis Smylie.

The 23-year-old, who is mentored by Cam Smith, is a new face on the golf scene after a breakout year in 2024. He's now -4 through 15 after consecutive birdies at 13 and 14.

And yes, he is named after The King.

Martin Watt
BBC Sport Scotland at the Renaissance Club

Bounce back!

Sepp Straka holes a delicious uphill chip from left of of the eighth green to recover one of those dropped shots.

It's now a three-way tie at the top.

Martin Watt
BBC Sport Scotland at the Renaissance Club

American Jake Knapp continues his blemish-free round by avoiding any mishaps on the par-three 17th to stay joint top.

He may be flying under the radar somewhat but has thrived in the East Lothian sunshine today.

Calum Hill has led the Scottish charge all day and the Kirkcaldy-born player makes par at the ninth hole to finish his round.

A bogey-free 65 has him third on the leaderboard.

Image source, Getty Images