American Justin Thomas has a cracking pair of white trousers on. Skinny legs, the slacks flutter in the breeze. He's gusting through Troon right now and has an eagle putt to reach five under... it looks good and is good is it? No. A fraction shy. That's birdie though and the outright lead.

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Phil Casey of the Press Association has a warning for the Wimbledon champion...

Jim Furyk is off to an absolute flyer. He takes a little luck on the par-five fourth as his long iron into the green missed the bunker by a foot to leave a long, long eagle putt. He rolls up and converts for birdie, taking his chance and using lady luck nicely.

Three under through four. Someone is shooting 64 today.

Colin Montgomerie must now switch from a 2-3-5 formation to a 5-4-1 with men behind the ball. This back nine will hurt you. It packs Ronaldo, Messi, Griezmann, you name it. Big guns.

He starts well on 10, rolling a long putt close to convert for par.  He's on the fairway on 11, Luke Donald is wayward from the tee box though. Way right.

Image source, Reuters

John McEnerney: Going for either Stenson (last time) or Shane "Burly" Lowry, my heart wants Sergio to win but my head knows it'll go all Pete Tong for him!

I like Lowry's chances too John. Not sure on Stenson, I think he folds too easily.

Tony Munky: Four birdies in seven holes in his back garden? Might as well give Monty the Claret Jug already.

Steady on Tony. What a story that would be.

Who do you fancy for the win this week? Tweet me on #bbcgolf.

In keeping with our chat on Americans performing at Troon, Patrick Reed has just wedged one in on three for eagle. Two bounces, in she goes. What a lovely start for a man who will be at the Olympics for the US.

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The fine start from Justin Thomas is in keeping with what American's tend to do here at Troon. They love it here and the last seven winners of the Open at this venue have come from the US.

They are Todd Hamilton, Justin Leonard, Mark Calcavecchia, Tom Watson, Tom Weiskopf and Arnold Palmer.

I think Monty will lead on his own shortly as Sanghee Lee was in trouble on seven. Marc Leishman has undone all of his good early work with a double bogey on nine to move back to level par.

Lee has a long par putt to stay top of the pile with Monty. What a putt. He just smashes it in. It was racing. I stand corrected, the lead will remain shared. And Justin Thomas has just started biride-birdie-birdie. We have a three-way share.

These pictures were the other way around earlier on. Excitement to sadness after one hole, then back the other way after nine.

Double bogey-par-birdie-birdie-par-birdie-par-birdie-birdie.

That's the Colin Montgomerie card. Did anyone see that coming?

South African Branden Grace is one of the game's emerging talents with a number of impressive wins to his name but as he wildly let's his club go on the first hole, ending the swing with it in one hand, you know trouble is coming. Bunker.

Colin Montgomerie is getting roared along and sets up a birdie chance on nine. It would be good to take this as things get tougher from here on in, much tougher in fact.

Nice from Grace from the sand, a foot or so left. Our leader Sanghee Lee is in trouble on seven as he buries one into the thick rough. 

Back to Monty on nine, lovely stuff. He is co-leader. Remember he was two over after one. Gutsy.

Here's some pairings we're getting excited about in the next hour or so:

08:25 - Padraig Harrington (Ire), Louis Oosthuizen (SA), Jamie Donaldson (Wal)

09:03 - Jordan Spieth (US), Justin Rose (Eng), Shane Lowry (Ire)

09:14 - Ross Fisher (Eng), Steve Stricker (US), Vijay Singh (Fij)

09:25 - Danny Willett (Eng), Rickie Fowler (US), Jason Day (Aus)

09:36 - Rory McIlroy (NI), Hideki Matsuyama (Jpn), Bubba Watson (US)

-3 Sanghee Lee (6)

-2 Colin Montgomerie (8), Marc Leishman (8), Luke Donald (8), Scott Gregory (4), Jim Furyk (2)

-1 Marcus Fraser (6), Ryan Palmer (5), Harris English (3), Steven Bowditch (3), Kevin Chappell (3), Justin Thomas (1), David Lingmerth (1)

Image source, Getty Images

The one hole we hear so much about this week is number eight - The Postage Stamp.

It's just 123 yards in length, incredibly short for what these players are used to. It's littered with problems and Marc Leishman finds some in the bunker.

Colin Montgomerie eats this hole up though. He shows it little respect by landing his iron on a slope and letting the ball trickle down to setup birdie. Can he roll this in... go get 'em Monty, great score.

Luke Donald from distance on the same hole... this one is going in all the way, birdie written all over it.

Can Leishman dig himself out of trouble? That's delightful. From the sand he used the Montgomerie approach and the slope leaves him a tap-in par. Wonderful golf wherever you look.

I'm a fan of the Darren Clarke shoes today. No prizes for fashion though, this isn't Royal Ascot. A par putt slides away on two.

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Jim Furyk, I just said we have to keep an eye on him. A leaderboard lurker, always hanging around, always ready to triumph with a steady approach. This time though he's flashy with bells on. Big putt on two and it's birdie-birdie.

Image source, .

Who's your money on over the next four days? It is not an easy competition to predict as this graphic shows.

Over the last 14 years, we have had 11 different winners, although there have only been winners from four countries - USA, Northern Ireland, South Africa and the Republic of Ireland in that time.

Marc Leishman walks off seven with a par but Luke Donald can go better if he sinks this 25ft birdie putt. A lovely weight, he stands dead still and eye-balls it... just wide. 

To Colin Montgomerie for birdie... it lacks weight and that's par.

Darren Clarke is a lucky guy on two as a poor strike comes up short but refuses to trickle into a bunker. Colin Montgomerie sets up an outside birdie chance on seven as he goes all Jordan Spieth and yells "be good" at his ball. Some 20ft left.

These are benign conditions, the scoring will be low. Someone will shoot 64 today if you ask me, seven under. Maybe even lower?

Could we see a 62? Never happened remember. Surely not?

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