I messed up but title defence still within my grasp, insists Spieth
Defending champion Jordan Spieth blamed a "brain fart" for the mistake which damaged his bid to become the first player to win back-to-back Open titles for a decade.
Spieth was three under par after 14 holes of his opening round at Carnoustie before running up a double bogey on the 15th, dropping another shot on the 16th and scrambling for a bogey on the 18th after driving into the Barry Burn.
The resulting 72 left Spieth six shots behind clubhouse leader and housemate Kevin Kisner as he seeks to emulate Dubliner Padraig Harrington in 2008 in holding on to the Claret Jug.
"The problem on 15 was on the second shot," Spieth said. "I should have hit enough club to reach the front of the green, and even if it goes 20 yards over the green, it's an easy up and down.
"That's what I would consider as a significant advantage for me, recognising where the misses are, and I just had a brain fart and I missed it into the only pot bunker where I could actually get in trouble, and it plugged deep into it.
"It was a really, really poor decision on the second shot and that cost me."
Spieth was among the morning starters who looked to have got the best of the conditions and the 24-year-old added: "Yeah, it felt like a missed opportunity. I felt like I was really going well.
"I don't see the winning score being any better than it was in 2007 (seven under par)"