Route 66 baby! Tyrrell Hatton has stuck his foot on the gas and travelled with the gusto of Dean Moriarty. Yasss!

The final stop of the day sees Hatton nab another birdie, moving him alongside Cameron Young on eight under.

They're sat staring at the crown of Dustin Johnson, who remains in the driving seat.

Now then... Scottie Scheffler has a birdie putt to climb alongside Hatton and Young... he's got it.

Some big names are on the road towards the Claret Jug.

Cam Macculloch: I played the Old Course in 1977 just after the Open one evening with the course in today's condition with a little rain and shot 75 (h'cap 5). I played in next year in March blowing a gale and shot 90. Someone could shoot 60 today if the wind stays low.

Three pars for this group at the par-three 11th. Well-handled with the pin tucked way over on the left and guarded by a few bunkers.

No change. On they go.

The Old Course has been very scoreable today, with Adam Scott's birdie on the 18th ensuring he has carded the lowest tally of the day.

The Australian, who finished second back in 2012, walks off with a serotonin-inducing seven-under 65.

And - after Sergio Garcia shot a 66, with Dustin Johnson and Aaron Wise signing for 67s - it means the Old Course is already taking more hits than yesterday.

Iain Carter
BBC golf correspondent on Radio 5 Live

Chance after chance after chance, Scheffler is creating, but he just can't take them at the moment.

Settles for par, and drops two behind the leader.

It was only a matter of time as they've been peppering the ninth green all day, and it's Sahith Theegala who lands the eagle two with a long putt from 50 feet across the putting surface that drops nicely into the cup.

Theegala only got into The Open last week when Daniel Berger pulled out injured but is taking full advantage now.

Back to Scottie Scheffler... can he match Johnson's birdie up ahead and move alongside Cameron Young?

Usually he eats these putts for breakfast.

Not this time! Scheffler is left hungry after his ball hits the left lip - I think, Tyrrell Hatton was blocking the view - and stays at ground level.

Oh no! I didn't see that coming. Jordan Spieth is on the move early as his short birdie putt at the 10th slides past on the right.

Golden opportunity passed up.

Steady pars for Jon Rahm and Harold Varner III. This group is yet to record a bogey today. Let's keep it that way, gents.

Dustin Johnson led the Open after two rounds on 10 under the last time it was held at St Andrews in 2015.

But he dropped back to four under by the end of the weekend to finish tied 49th as his namesake but no relation, Zach Johnson, won the Claret Jug in a play-off.

Image source, Getty Images

And the new top of the pops.... Dustin Johnson.

The former world number one takes the outright lead by knocking his birdie putt on the last.

Excellent round from Johnson. After starting with a bogey on the first, he doesn't drop another shot and lands six birdies to put him into the clubhouse lead.

But... and there's always a but... Dustin Johnson might yet move further ahead if he birdies the last.

He's got more than a chance you know.

After reaching the 18th green in two, Johnson's eagle putt saunters up towards the hole and leaves him eyeing up a birdie.

Seconds later, Scott beautifully judges his eagle putt and should also scribble a birdie four on his card.

Iain Carter
BBC golf correspondent on Radio 5 Live

It got a bit stodgy around the 12th and 14th holes but the pace was better. I think the bad news is that it will get worse later, when everyone is on the course.

But each group has a course official with them today, so hopefully it won't be as farcical as it was yesterday,

I say farcical but it is part of the uniqueness of this course.

Watch the best of a stunning round by debutant Cameron Young - who produced the second-lowest opening round ever at the Open at St Andrews.

It's a surprise to some extent, and we know Young hasn't won on the PGA Tour yet, but he finished second at the PGA and has also had a couple more runners-up finishes this season.

Leading The Open, at the home of golf, is a totally different story though...

Jordan Spieth is dialled in! After covering the front nine in 32 blows, the 2017 Champion Golfer of the Year sticks his approach at the 10th to about five feet.

Yet another birdie chance coming up - he's soaring today!

Scottie Scheffler makes it look so easy. After bending a drive around the hotel, the Masters champ is left with 150 yards to go on the 17th.

A short iron is nuzzled into the green, leaving Scheffler with another very makeable birdie putt.

Watch out Dustin Johnson and Cameron Young, three could about to be a crowd.

Zane Scotland
Former European Tour player on BBC Radio 5 Live

Tiger has been hobbling and it may be a better on the back nine for him.

He has played some decent golf today but he hasn't got his putting boots on.

Oh hello! Just as he did on the first, Ian Poulter finds the bottom of the cup with another putt from way downtown on the third!

Birdie-bogey-birdie start for the Englishman.

Alex Bysouth
BBC Sport at St Andrews

John Daly and Bryson DeChambeau sparked a bit of a bromance during their opening round. It was the first time they have played together and Daly spoke highly of his big-hitting protégée afterwards - likewise Bryson about his compatriot.

DeChambeau was on the putting green by the first tee super early yesterday but just popped down and for two or three efforts before his round today. Daly greeted him with a hug, while Little John on the bag got a big high five. A whole lotta love in this match.

It's another decent birdie try from Woods but his ball just hasn't got enough juice to make it all the way to the hole.

Pars for Homa and Fitzpatrick - who despite being US Open champion is playing second fiddle to Woods in this group among the crowd.