Jon Rahm takes the tournament by the scruff!

The Spaniard sinks his birdie putt to move to five under and exclusive occupancy of the lead.

Can Brooks Koepka survive the tricky 18th?

He gets his driver out and whacks the ball straight down the fairway. Off to a good start.

Tiger Woods is being minced by this Portrush course.

A fifth bogey in the last six holes and he is six over for his round. And there are another eight punishing holes to come.

After three birdies on the back nine, finishing with a bogey is a bit of a blow for Tyrrell Hatton.

But the 18th has claimed many scalps today and the Englishman still goes into the clubhouse one off the lead.

We may have jinxed Brooks Koepka...

After saying he would surely make par, the four-time major winner taps a fairly straightforward putt to the right of the 17th hole for a rare bogey.

Take a bow, Ryan Fox.

The New Zealander finishes off the lowest total for a back nine in Open history with a birdie on the 18th. He holed six birdies in total to make that 29 over the last nine holes.

Alex Bysouth
BBC Sport at Royal Portrush

The screams greeting Tiger’s tee shots are getting more beer-fuelled and raucous. Mind you I saw one couple cracking open a bottle of Prosecco a moment ago so maybe it’s the bubbly that’s done it... not sure the American is finding such hollers particularly welcome.

If he is going to turn it around, Tiger Woods is yet to yank up the handbrake and spin the wheel.

The 15-time major champion is five over at the turn. This could turn into a real wreck of a round.

Jon Rahm joins Tyrell Hatton, Brooks Koepka and Shane Lowry in a share of the lead.

Now, can he hang in there when the going gets tough over the next 10 holes?

Jon Rahm is sniffing a share of the lead.

Fresh off picking up a stroke with a birdie at seven, he stiffs his approach on eight right at the flag. That is six feet away.

If it drops, Lowry, Hatton and Koepka have company.

Of course Brooks Koepka is going to make par.

The man is a machine. He chips on from the back of the 16th green and leaves himself with a straightforward putt for three.

A superb putt from Tyrrell Hatton!

He strokes it in for a birdie on the 17th to join Shane Lowry and Brooks Koepka at the top of the leaderboard.

The Englishman is yet to drop a shot today.

Dustin Johnson patches up his round as he hits the turn with a nicely taken birdie on nine to move back to level par.

Tony Finau, who is wearing a black and white top with a delightfully loud print, kicks off the back nine with a birdie.

Co-leader Brooks Koepka smacks the ball down the par-three 16th and it sails over the green. Another birdie would be a big ask here.

Tiger Woods' birdie putt, perhaps suckered out of some pace by the wet greens, holds up just short on eight. Par.

Iain Carter
BBC Sport golf correspondent at Royal Portrush

Rory McIlroy seems to struggle when he gets into the spotlight. His best golf comes when he is out of contention and can freewheel to get back into it.

Tommy Fleetwood opts to chip onto the 16th green and he nails it. The ball lands inches from the hole and he can tap in for par.

Good decision, Tommy. If he can squeeze a birdie out of the next two holes, he'll be tied for the lead.

Michael Davis: When did Rory last have a good first round in a major? Most times he is so far back after 18 jokes that it’s all over!

Image source, PA Media

Tiger Woods second on eight is a bit more like it, finding a bit of traction and grip.

Patrick Reed's attempt is closer though, holding up just eight feet away.