The world tennis number two Andy Murray has suffered a surprise third round loss at the Indian Wells tournament in California.
Murray squandered a 4-1 lead in the third set before losing a tiebreaker to world number 53 Federico Delbonis of Argentina.
Delbonis took advantage of a series of Murray errors to run off the last five points of the decider.
Delbonis, who reached the quarter-finals this year in Rio and Sao Paulo, varied his strategy against Murray and took advantage of some weakness in the Scot's serve.
Murray failed to register an ace and won less than 50 percent of his second serves.
"I know it was a challenge," said Delbonis. "I have to mix (my shots) all the time.
"In the end, I can do my job and this is what I get."
It was a short appearance in only the second tournament of the year for Murray, who lost in the final of the Australian Open to world number one Novak Djokovic.
Delbonis will meet Frenchman Gael Monfils in the fourth round after the 13th seed dispatched Spain's Albert Ramos-Vinolas 6-1 6-3.