Novak Djokovic survived a mighty scare before sinking wild card Jenson Brooksby in their US Open fourth round clash and staying on course for an historic calendar grand slam.
The world number one was blitzed 6-1 in an astonishing first set by the 20-year-old American, who produced just a single unforced error as he served out nervelessly to take the opener in just 29 minutes.
It took Djokovic until midway through the second set to stem his opponent's remarkable momentum in front of an increasingly raucous home crowd on Arthur Ashe court.
Novak Djokovic produced a stunning comeback after being hammered in the first setInsurance Loans Mortgage Attorney Credit Lawyer
Jenson Brooksby (right) was a wildcard and was in stunning form early on before fading
After ultimately wrapping up a 1-6 6-3 6-2 6-2 victory in three hours, Djokovic admitted: 'It wasn't a good start but I expected a battle and I got one. I'm pleased that I could overcome it.
'It's different stepping out on the court for the first time against an opponent who really has nothing to lose. He's a young, talented player who has got the all-round game.
'He had the crowd behind him, of course, and he played a perfect first set. Everything he intended to do he executed it perfectly. I think we're going to see a lot of him in the future.'
If there was an air of inevitability about Djokovic's eventual recovery, the performance of Brooksby, who was ranked outside the world's top 200 four months ago and had never previously faced a top 10 player, was wholly unexpected.
Playing with power and almost perfect depth, he blew his illustrious opponent off the court in the opener and show no signs of ailing in the second, despite Djokovic releasing a huge surge of emotion after breaking to go 2-0 in front.
Brooksby simply responded by converting his sixth break point chance in a fifth game of the set that lasted almost half an hour alone, although Djokovic's ability to immediately re-establish his advantage ultimately proved to be the turning point.
Djokovic has set up a semi-final clash with Matteo Berrettini, who he beat at WimbledonInsurance Loans Mortgage Attorney Credit Lawyer
Whilst his performance came as a surprise to