The United States' J.B. Holmes holds a one-shot lead over Ireland's Shane Lowry after the first day of The Open at Royal Portrush in Northern Ireland ©Getty Images

The United States' J.B. Holmes holds a one-shot lead over Ireland's Shane Lowry after the first day of The Open at Royal Portrush in Northern Ireland.

Holmes carded a five-under-par round of 66 on the links course in County Antrim.

Despite bogeying the first hole, the American went onto make three birdies in the next four holes to move onto two under.

Further birdies followed at the 12th, 14th and 18th as Holmes set about improving on his best-ever finish at The Open and any of the four majors – third in 2016.

"That is the biggest part of it," Holmes told Sky Sports about the challenge of links golf.

"You have to accept the wind, the rain and the bad bounces and accept the circumstances you are in. 

"It is a mindset you have to get into.

"The rain has been much worse. 

"I hit it really good off the tee and just played solid."

Lowry set the early standard with five birdies, and one dropped shot, for a round of 67.

He is followed by a flurry of players on three under, including world number one Brooks Koepka of the US.

Koepka, the winner of four of the last nine majors in which he has competed, is joined by the likes of Spain's two-time runner-up Sergio Garcia and New Zealand's Ryan Fox, who recorded the lowest total for a back nine in Open history, taking just 29 shots.

Northern Ireland's Rory McIlroy had a day to forget as his bid for a home Open win was left in tatters ©Getty Images
Northern Ireland's Rory McIlroy had a day to forget as his bid for a home Open win was left in tatters ©Getty Images

It all came on a day when world number three Rory McIlroy’s bid for a home Open victory all-but ended after a disastrous round. 

The Northern Irishman finished with an eight-over-par 79 having made a quadruple bogey on the first hole and double and triple bogeys at the 16th and 18th, respectively. 

"I would like to punch myself," McIlroy, a four-time major winner and the 2014 Open champion, told BBC Radio 5 Live.

"I made a couple of stupid mistakes.

"I was pretty nervous on the first tee and hit a bad shot.

"I showed some resilience in the middle of the round and was trying to fight back into the championship but then I finished off poorly as well.

"If I look back, I undid all my good work to recover on the last three holes.

"At the end of the day, I play golf to fulfil my ambitions, not anyone else's, but I wish I could have given the crowd something to cheer about.

"I let myself down more than anyone else and need to pick myself back up."

Three-time winner Tiger Woods is only one shot better off then McIlroy after the American produced six bogeys and a double bogey in his round of 78.

World number four Justin Rose of England is two under, while the US's Jordan Spieth, who won the event in 2015, is one under.

Italy's Francesco Molinari faces an uphill battle to defend his title after finishing on three over.