Rory McIlroy left counting the cost of another late lapse - with the Northern Irishman's shocking double bogey changing the complexion of the DP World Tour Championship
After 35 holes when he looked like the Rory McIlroy of old came a calamitous 36th featuring the sort of careless mistakes that have haunted him all season.
From seemingly cruising to a second victory in consecutive starts for the first time since his all-conquering year of 2014, the Northern Irishman's shocking double bogey at the 18th changed entirely the complexion of the DP World Tour Championship.
Thankfully for McIlroy, it came on Friday rather than on Sunday afternoon but it is going to be fascinating to see what happens on Saturday. A blip from his serene progress or one that sees the doubts resurface?
He has certainly given plenty of encouragement to the men who thrive on such frailty. How about the last two Open champions, for starters?
Standing on the 18th tee, one stroke ahead of his old pal Shane Lowry, you would have bet your bottom dollar on the pair teaming up for today's third round with Rory probably two shots ahead.
But the four on offer at this classic risk-reward par five became a seven as McIlroy followed one error with another, driving into a bunker, then finding the water hazard with his third shot and stubbing the subsequent chip.
It turned what would have been an encouraging 67 into a so-so 70. McIlroy did not just lose the lead, he fell to a tie for fourth place and is now just one stroke ahead of Collin Morikawa.
'Hopefully, that's the bad one out of the way,' said McIlroy. 'I'm playing really well and 70 was about the worst I could have shot.'
This was another good day for Morikawa, whose second successive 68 saw him take another assured stride to what will surely lead to him becoming, at the very least, the first American to win the season-long Race to Dubai. He could, of course, end up doing it in style if he wins the final event as well.
Lowry began the week saying he could not wait to get home after a hectic season.
'I'm running on the smell of an oily rag,' the Irishman commented, with a colourful take on the old saying about running on fumes.
After rounds of 69 and 65, and with a first victory since his Open triumph at Portrush in 2019 now in his sights — not to mention the £2.5million first prize — it might be that the oily rag now has the scent of the most intoxicating perfume.
Alongside Lowry at the top are American John Catlin and England's Sam Horsfield, who has the opportunity to transform a season currently well short of his breakthrough campaign in 2020, when he won twice.