Having found the bunker on the last, Hovland faces another test on the par-three eighth. He's long and left, but he must wait for Patrick Cantlay to finish the 10th before he can putt.

But once again, the Norwegian is up to the task. He still has a knee-knocker for par, but that was a good effort from off the green.

McIlroy is technically putting for a birdie, but he's just looking to get it close to the hole, which he does.

Both players hole out for par and move on.

Kat Downes
Commentator on BBC Radio 5 live

The love for Rory McIlroy spreads far and wide. This couple have come all the way from St Louis to support their man.

I guess the only tricky thing is making sure they stand the right way round...

Image source, BBC Sport

Image source, Getty Images

He may have been hit-and-miss on the greens, but one thing Dustin Johnson can do is hit the long ball - and his drive on the ninth is a stunner.

It's a gimme birdie hole today but DJ is not a million miles from acing this for an albatross as his monster drive takes a soft landing and rolls nicely pin high to the left of the flag!

Eagle try coming up...

Jonnets: The putter is just not working for Cameron Smith today yet.

Has he tried turning his putter off and then turning it back on again?

Iain Carter
BBC golf correspondent on Radio 5 Live

Cameron Smith misses again and he bends in frustration and you can hear the reaction from the crowd.

Another missed opportunity for the Aussie.

Cameron Young splashes out nicely but can't escape with a par.

While our eyes have been trained on Young's troubles, the other Cameron quietly cooks up a golden chance of a birdie.

Smith's missed it!

Not seen movement like that over a short distance since trying to negotiate a playground rope bridge as a kid.

A wobble here, a wobble there and the ball falls off line.

Alex Bysouth
BBC Sport at St Andrews

Things have slowed down a tad on around the turn, with play becoming congested - McIlroy and Hovland had a bit of a wait to hit their tee shots at the par-three eighth. They have to account for the other tee boxes and greens around this spot also trying to crack on.

Slow going for Matt Fitzpatrick on the front nine, but he's on the move now!

Three birdies in a row from the ninth takes the US Open champion into a tie for 10th, six back of Hovland.

Just can't get moving these two, with DJ left with a lengthy par save which he converts to stay at 10 under.

Scheffler has a birdie try that he can't quite manage to sink, and although they've both been playing pretty well so far they've not quite for the hang of the greens as yet.

Iain Carter
BBC golf correspondent on Radio 5 Live

Oh my word a massive error - he has gone into the deep pot bunkers shared with the 7th and 12th.

The Old Course bites the error and Young looks to the skies.

It's easy to forget Cameron Young is an Open debutant.

The American has played clinically, calmly and showed few nerves up to this point.

But here's his first little wobble.

A duffed chip on the seventh ends up in the sand and it's so deep he's going pot-holing.

BBC Radio 5 Live's Andy Stevenson sent me this photo, to be captioned: Spot the doughnut.

Never mind that Andy, it's a great view you've bagged yourself there. He's got the job of grabbing those first thoughts from the players after they've checked their numbers and signed their scorecards.

Which, dependant on how they've played, could be the easiest, or toughest job going.

Click the link to hear at the top of the page to hear commentary from the team out on the course.

Image source, BBC Sport

Hang on... there is some more movement on the leaderboard.

It's Patrick Cantlay! He's creeping around in the shadows, quietly stalking his prey and ready for the kill.

After lagging a long eagle putt on the ninth, he knocks in for the birdie and goes into outright fifth.

Shane Lowry rolls his birdie putt in at the 18th, prompting a big cheer from those packed into the grandstand.

The Irishman cracks a wry smile, knowing that he had the makings of a glorious round after those two chip-in eagles around the turn.

He may have stuttered down the stretch, but the 2019 champion has provided first-rate entertainment today.

Andrew Murray
BBC Radio 5 live commentator

Hatton is perfectly within his rights to comment to the referee if he feels that they are losing their position in the field.

It doesn't take much to upset Tyrrell as we know but if you get on the wrong side, we all know what he can be like.

-14 Viktor Hovland (7)

-12 Rory McIlroy (7), Cameron Smith (6), Cameron Young (6)

-10 Patrick Cantlay (8), Dustin Johnson (7), Scottie Scheffler (7)

Full leaderboard

Tyrrell Hatton is not having a great time of it out there. A par putt on the eighth sneaks off to the right and he'll move back to seven under, one over for the day.

Seasoned golf fans know holding a 36-hole lead doesn't necessarily mean that person will go on to lift the trophy on Sunday.

And that's been shown on a few occasions at the Open in recent years.

Louis Oosthuizen set a tournament record for the lowest 36-hole score with 129 (11 under) at Royal St George's last year - but lost to Collin Morikawa.

A famous example also came here at St Andrews in 2015.

Dustin Johnson - one of the men chasing Cameron Smith's overnight lead today - blew a one-shot lead going into Saturday and ended up finishing well down the leaderboard as namesake Zach Johnson won.

"Sit!"

Not quite, Rory. His approach to the seventh is a little heavy-handed and leaves him around 20 feet or so for a third successive birdie.

Hovland finds himself in the cavernous 'Shell' bunker. He connects well and it comes up just shy - will it fall back down the slope?! No, of course it doesn't - things are going his way today.

McIlroy's birdie putt trickles off to the left. No problem - he's keeping the bogeys off the card and that's the main thing at this stage.

Can Hovland make it five in a row? Not this time! It races past on the right but he gladly accepts take his par having been bunkered off the tee.