SOUTHPORT, England — Jordan Spieth’s ball was nestled in the knotty grass on a knoll, more than 120 yards right of the fairway he had aimed to reach. His hands flew to his head in mortification as he watched the shot’s wayward path. His first thought was that he would be lucky to escape with a double-bogey 6 on the hole, No. 13.

The three-stroke lead that Spieth had carried into the final round of the 146th British Open at Royal Birkdale was gone when he reached the 13th tee on Sunday. Spieth was tied with Matt Kuchar, the other competitor in his pairing, and he tried to block out memories of the last time he had frittered away a final-round lead at a major. But he felt the same helplessness, the same nagging doubt, as he had at the 2016 Masters, where he lost a five-stroke lead in the final nine holes.

Spieth knew he had to close out this major to throw dirt over the memory of that collapse and, as he said, get “over the hill.” But the hill on which Spieth’s ball came to rest was better negotiated by a goat than a golfer.

As he surveyed the situation and mentally checked off his options, he was calmed by something his caddie, Michael Greller, had told him six holes before. During a recent vacation in Cabo San Lucas, Mexico, Spieth had posed for a group photograph with several other athletes, including the basketball player Michael Jordan and the swimmer Michael Phelps, both considered the greatest ever in their sports.