British number one Cameron Norrie's run in Indian Wells ended with an error-strewn defeat against American Frances Tiafoe in the quarter-finals.
Norrie, who won the event in 2021, was well below his best and beaten 6-4 6-4 by the 25-year-old 14th seed.
Norrie, 27, the 10th seed, looked unusually flat at times and made 28 unforced errors.
"I'm disappointed," Norrie said. "It was a big opportunity for me looking at the names left in the draw."
He added: "I felt I had a really good chance to win another Indian Wells but on the day today Frances was better than me, and that's the sport."
Tiafoe will play Russian fifth seed Daniil Medvedev or Alejandro Davidovich Fokina of Spain in the semi-final.
He reached the semi-final of the US Open last year but this is the first time he has reached the last four of a Masters 1000 event.
"It is big," he said. "I'm super happy about today.
"I have been playing really well all week. I am happy being here."
The opening stages of the match were interrupted by drizzle in the desert but afterwards Tiafoe was comfortably the better player in windy conditions.
He broke serve at 3-3 in the first set before closing out the set and soon took a 5-2 lead in the second.
Norrie won the next two games but Tiafoe closed out the match on his serve on the second attempt.
"I think Frances dealt with the wind better than me," Norrie said,
"Usually I'm really good in the wind but I felt I didn't really play smart.
"I could have been a bit more aggressive against the wind and a bit more controlled with the wind and tried to keep the rallies a bit longer. He was really good in big moments."
The defeat ends the British singles interest in Indians Wells, one of the most high-profile tournaments outside of the Grand Slams, after Jack Draper and Emma Raducanu were beaten on Tuesday.