If anybody thought Rory McIlroy was in an unassailable position when he teed off four clear at The Masters Tournament they were quickly made to think again.
While McIlroy three-putted the first for bogey and struggled hard for a par five on the next, South African Charl Schwartzel opened with a chip-in birdie and then produced something even more dramatic.
The 26 year old, who has never had a top-ten finish in a Major, spun his pitch to the 350 yard third into the hole for an eagle two and joined McIlroy out in front at 11 under par.
And they had Tiger Woods putting in a charge too. Joint ninth and seven adrift overnight he birdied the second and third and then came back from three-putting the fourth by holing from eight feet at the sixth and seventh.
The four-time champion was up to joint third place and only three back - and this, of course, after 17 months and 20 events without a victory as he dropped from World Number One to seventh in the rankings.
McIlroy paid the price for pulling his approach just a touch on the opening hole. His first putt was just off the green went five feet past and he missed it.
Then came a drive into the sand on the next and his recovery hit the lip, leaving him 250 yards for his third shot - and that found another bunker.
Getting up and down from long range was some achievement, but the roars up ahead told him that things were changing.
Luke Donald was in the hunt too, making birdie at the second and remaining eight under with Woods, Australians Adam Scott and Jason Day, Korean K J Choi and Argentina's 2009 champion Angel Cabrera, who followed a birdie at the second with a bogey on the next after flying the green.
McIlroy then had a great chance to get his nose back in front on a sweltering afternoon, but he missed from six feet on the third in another worrying sign.
Last year's runner-up Lee Westwood turned in 33, but at six under he was still five back.
As McIlroy parred the fourth there was another almighty noise from nearby.
It was not Schwartzel this time - he three-putted the fifth to slip one back - but Woods, who unbelievably hit his second shot to ten feet at the uphill 570 yard eighth and made it for eagle.
Now five under for the round already - and that with a bogey in it - he joined Schwartzel on ten under to be only one behind.
