Jon Rahm moved into the outright lead through nine holes of his opening round at The Open as Brooks Koepka shot into contention - but Tiger Woods endured a miserable day at Royal Portrush.

Spaniard Rahm, a man in form having won the Irish Open at the start of the month for the second time in his career, was in fine touch on the Dunluce Links.

Rahm made birdies at the second and fourth holes before picking up three straight gains before the turn to reach five under through nine, lifting him one clear of clubhouse leader Shane Lowry.

Koepka, who has gone 2-1-2 in the first three majors of 2019, was two under par by the turn and picked up further strokes at 12 and 14, which at the time left him in a share of the lead.

The four-time major winner dropped a shot at 17 to fall into a stacked pack at three under, a score Tommy Fleetwood, Tyrrell Hatton and Ryan Fox all achieved after 18 holes – the latter having recorded the lowest back nine in Open history with 29.

Woods was toiling much further down the leaderboard, though. The Masters champion went bogey, double bogey, bogey between the fifth and seventh holes.

He dropped further shots at the ninth and 10th and the American was six over with eight holes to play.

Earlier on Thursday, home favourite Rory McIlroy toiled to a 79 in front of an expectant crowd. He started with a quadruple-bogey eight and finished with a seven on the par-four 18th.