The oldest player on the men's circuit, Santoro, who will turn 37 next month, confirmed after a 6-4, 6-3 defeat that he was now retiring.
"I've had lots of fun but now it is time to take a break," he said after his 15th and final Paris Masters appearance.
The pocket-sized Santoro, once nicknamed "the magician" by Pete Sampras for his habit of mystifying bigger, stronger opponents, had earlier suggested he might play the Australian Open in January before bowing out. "It was a good match played in a great atmosphere and that's what I wanted," said Santoro, who traded shirts with Blake and was hugged by the American after match point.
"I don't feel sad, I feel relieved in a way," added the Frenchman, who played a record 69 Grand Slam tournaments.
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