Jordan Spieth rued a "brain fart" at the 15th hole that halted the momentum he had garnered during round one of his Open Championship defence.
The three-time major winner was going nicely at three under through 14 holes, but a six iron into a fairway bunker meant his third shot had to be played out to the left and eventually cost him a double bogey.
Further wayward striking led to dropped shots at the 16th and 18th holes as Spieth signed for a one-over-par 72, which was six shots back of clubhouse leader Kevin Kisner.
And the American acknowledged his opening round was a missed opportunity to be further up the leaderboard.
"It was an easy decision. I just hit the wrong club [at 15]," he said.
"I hit a four iron off the tee. I thought it was locked up and it ended up in the fescue.
"I hit a lot of shots I didn't think were as good and I walked up and kind of got good breaks, especially starting the round.
"But the problem was on the second shot 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.
"And that's what I would consider as significant advantage for me is recognising where the misses are, and I just had a brain fart, and I missed it into the location where 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.
"It felt like a missed opportunity. I felt like I was really going well. I had a nice par save after driving it in the bunker at six.
"Other than that, it was very stress-free. I was putting the ball where I needed to, having maybe no more than fewer feet for par on every hole. It was just a clean round of golf."
Despite his disappointing finish, Spieth is confident he can claw his way back into contention for the Claret Jug.
"I think I'm certainly in a recoverable situation. I mean, I imagine this is as easy as the course could play," he added.
"I don't see the winning score being any better than it was in 2007 with [Friday's] forecasted tough conditions and Sunday's forecasted heavy winds.
"It's not a bad place to be. You know, a solid round to stay in the top 25, top 20 will be kind of the goal to feel like I can do something on the weekend."
|Jimmy Butler aims dig at Timberwolves following 76ers home debut|
|Koeman surprised by dominant Netherlands|
|Southgate rallies England ahead of Nations League decider|
|Chile 2 Costa Rica 3: Waston brace sinks La Roja|
|Tite inspired by Guardiola´s City|
|Argentina 2 Mexico 0: Funes Mori´s header helps to sink El Tri|
|Lovren ready for ´fiery´ England clash|
|Brazil captain Neymar pleased with stern Uruguay test|
|Ravens´ Flacco doubtful, Jackson could start|
|Richarlison: I want to be at the Copa America|
|Tabarez buoyed by inexperienced Uruguay|
|Howell fires 64 again to extend RSM Classic lead|
|I´m proud of them - Giggs still upbeat despite Denmark defeat|
|Mancini ´very sorry´ for Ronaldo absence|
|Neymar clinches anything-but-friendly win for Brazil over Uruguay|
|Cipriani-inspired Gloucester thrash Tigers|
|Djokovic makes it three wins from three at ATP Finals|
|Germany relegated from Nations League top tier to cap miserable 2018|
|Fulham will back Ranieri in January transfer window if required|
|Brazil 1 Uruguay 0: Neymar penalty settles tight contest|
|Netherlands 2 France 0: Wijnaldum & Depay decisive as Germany are relegated|
|Wales 1 Denmark 2: Jorgensen and Braithwaite seal Nations League promotion|
|Oxlade-Chamberlain targeting early return|
|New Zealand-born Aki will ´relish´ facing All Blacks – Marmion|
|Portugal cannot focus on absent Ronaldo - Santos|
|Ramsey reiterates he wants to stay with Jaguars despite cryptic tweet|
|We tried to hit a home run and it didn´t work out - D´Antoni explains Carmelo exit|
|West Ham´s Zabaleta backs Premier League´s VAR introduction|
|Southgate eyes winning end to England´s ´brilliant year´|
|Patient Zverev seizes opportunity to make amends at ATP Finals|
|Rodgers: Packers still believe they can make playoffs|
|Mahomes hoping to ketchup to Heinz´s touchdown target|
|Ranieri tells Fulham fans not to expect repeat of Leicester ´fairytale´|
|Brown to leave role as RFU chief executive|
|Croatia star Rakitic ruled out of England clash|
|Capital gains for Zverev as he secures last-four spot in London|
|Sancho rise continues with Player of the Month award|
|Jones-Buchanan, Ablett and Briscoe sign new Rhinos deals|
|Root leads from the front as aggressive England assume control|
|Croatia´s Lovren antagonises Ramos and ´rude´ Spain|
|Rakitic has ´enormous respect´ for England ahead of Nations League decider|
|Ireland make flanker switch with Leavy out of All Blacks clash|
|Pakistan rip through Black Caps in Abu Dhabi|
|WATCH: Barcelona mark 15-year anniversary of Messi´s first match|
|Sterling, that you? - Walker uses falling fan to poke fun at England team-mate|
|Fleetwood applies pressure on Molinari, Wallace leads in Dubai|
|Don´t talk to me about VAR – Rakitic not over World Cup final loss|
|Van Dijk leadership essential for Liverpool – Wijnaldum|
|Dalic: Croatia´s bench was ready to stop Spain!|
|Sublime Root century gives England imposing lead|
|Vinicius appreciates Solari influence at Real Madrid|
|Havertz would suit Bayern Munich – Kimmich|
|Wilder: Roach recruitment a sign of Fury nerves|
|Ranieri targets defensive improvements at failing Fulham|
|PSG close investigation into player recruitment practices after finding no discrimination|
|Mayweather: Nasukawa exhibition back on|
|Witsel: Joining Borussia Dortmund my best career decision|
|Ballon d´Or win would not change Modric´s ´best year´|
|Ireland v New Zealand: Opta stats behind the meeting of the world´s top two|
|The Breakdown: A statistical look at Saturday´s rugby internationals|
|Batshuayi dismisses reports of Valencia departure|
|Brazil must make Copa America final – Tite|
|Rockets rout Warriors as Green goes scoreless|
|Seahawks rally past Packers|
|Lakers G Rondo to miss 4-5 weeks|
|Durant is done with questions about Green|
|Smith, Warner set to return to IPL in 2019|
|No rivalry between Mbappe and Griezmann – Deschamps|
|Neymar: Emery will bring success to Arsenal|
|Jedvaj backs Croatia to deliver against England|