Alexander Zverev rued a missed opportunity to win the Indian Wells Masters as he crashed out in the quarter-finals at the hands of home favourite Taylor Fritz.
American Fritz saved two match points to pull off an upset 4-6 6-4 7-6 (7-3) win over Olympic gold medallist Zverev.
Third seed Zverev was aware he had become hot favourite to triumph in California after Stefanos Tsitsipas crashed out to Nikoloz Basilashvili earlier on Friday, with US Open champion Daniil Medvedev already eliminated.
And the German was frustrated with his performance against Fritz, which left him unable to add to the Masters 1000 titles he has already won in Madrid and Cincinnati this year.
"It was just not really my day, to be honest," said Zverev, who had beaten Jenson Brooksby, Andy Murray and Gael Monfils to reach the last eight.
"I was close to winning, but the level of tennis was just not there for me.
"Mentally this is not easy for me. My next tournament is Vienna, so hoping I can deal with it well there, but right now I just want to go home.
"It was a very long season and I have played well but this one hurts because I knew that, after Stefanos lost this morning, I was kind of the favourite to win this tournament, but my tennis wasn't there yet."
— ATP Tour (@atptour) October 16, 2021
Zverev had won 20 of his previous 21 matches on hard courts and led 5-2 in the deciding set.
But Fritz was not to be denied, firing 36 winners to secure the second top-five win of his career, with this triumph adding to impressive victories over Italian duo Matteo Berrettini and Jannik Sinner this week.
Fritz said: "This is the farthest I've ever been in a big tournament.
"It is easily the best win of my life, against a really tough opponent on arguably the biggest match I could possibly play, so it's great.
"The biggest thing was match point down, I wanted to make him serve it out, so I just fought as hard as I could to hold that game.
"Then I got fortunate in his service game and from there I felt in control and felt really good under the pressure. I kept fighting. The crowd pushing me on meant so much.
"It is amazing. Especially the way that match ended with such high emotions with the crowd. The crowd was amazing and it is a dream come true."
— ATP Tour (@atptour) October 15, 2021