London, November 10: When Jack Sock lambasted himself for choking after a first-round capitulation at the US Open, he might have wished his season could end there and then.
The American squandered a two-set lead against Australian Jordan Thompson to fall at the first hurdle in his home grand slam just over two months ago.
Sock, who also bowed out in the opening round of the French Open, pulled no punches with a damning verdict of his performance at Flushing Meadows.
"Utter disappointment when you're up two breaks in one set, a break in the fifth, to choke it all away," said the 25-year-old.
Just one victory in his next three tournaments was certainly not a sign of things to come, yet Sock started the Paris Masters with an outside chance of pulling off a highly unlikely late raid for a place in the ATP Finals.
Pablo Carreno Busta occupied the eighth and final qualification berth, but the Spaniard's first-round exit in Bercy left the door ajar for several players to sneak in.
Sock needed to win his first Masters title to make his debut at the O2 Arena and duly defied the odds to prolong his season, beating qualifier Filip Krajinovic in a showdown which nobody could have predicted.
The Nebraska native said he was oblivious to the fact he was still in the frame to grace the courts in London when he got what he thought would be his final tournament of the season under way.
Sock was 24th in the Race to London before striking a ball in anger in the French capital, but was like a man possessed as he stormed to the biggest title of his career and moved into the top 10 in the rankings for the first time.
He was due to be at Augusta playing golf this week with John Isner, but will instead be facing Roger Federer, Alexander Zverev and Marin Cilic in the round-robin stage of the season-finale, rather than teeing off with his close friend in Georgia.
Sock will start his maiden ATP Finals as a long shot to take the prestigious title, but, as he said after his stunning victory triumph week, "crazy things can happen. That's sports and that's why we play."