Rory McIlroy made a quadruple bogey on the first hole and triple bogey at the last as his bid for a golf’s home British Open victory at Royal Portrush was left in tatters.
The 2014 winner, playing in his home country of Northern Ireland, sent his first tee shot out of bounds and ended his round ingloriously.
McIlroy finished with a round of eight-over-par 79 – 12 strokes behind clubhouse leader Shane Lowry.
World number one Brooks Koepka made a promising start to his opening round.
The 29-year-old American, seeking his fifth major since 2017, made birdies on holes two and five in a group that includes 2010 champion Louis Oosthuizen. His compatriot and 2017 champion, Jordan Spieth, also looked in good form, having moved to three under after six holes.
Three-time winner Tiger Woods is playing alongside fellow American and 2018 Masters champion Patrick Reed and England’s Matt Wallace, while world number four Justin Rose, tied second in 2018, is with American Tony Finau and Dane Lucas Bjerregaard.
Much of focus in the build-up to the championship was whether, come Sunday, Northern Ireland would be celebrating their greatest hope lifting the Claret Jug on the country’s premier course.
But the chances of that happening have all but disappeared as the 30-year-old evoked memories of his final-round collapse at the 2011 Masters, with an inward nine that included a double bogey on the 16th and a triple bogey on the 18th. The quadruple was his first in a major since the 2013 US Open.
“I would like to punch myself,” the four-time major winner 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.”
Irishman Lowry set the early standard with five birdies, and one dropped shot, for a 67, while 22-year-old Scot Robert MacIntyre, playing in his first Open, produced an eagle at the fifth and finished his opening round a shot behind.
Spanish two-time runner-up Sergio Garcia and 2012 US Open winner Webb Simpson also had strong days to join a group on three under.