Dominic Thiem defeated Milos Raonic in three sets to secure a place in the BNP Paribas Open final at Indian Wells, where Rafael Nadal withdrew from the other semi-final against Roger Federer because of a knee problem.
Austrian Thiem battled past Raonic, the world number 14, to record a 7-6 (3) 6-7 (3) 6-4 victory in just over two-and-a-half hours on Stadium 1.
Earlier on Saturday, Nadal announced he had reluctantly been forced to pull out of a showdown with Federer.
The Spaniard had looked in serious discomfort as he saw off Karen Khachanov in the quarter-finals, needing a medical time-out after the third game of the second set to have tape applied under his right knee.
Nadal, the number two seed, confirmed he felt unable to give his best in what would have been a first clash against Federer since the final of the Shanghai Masters in October 2017.
"As I said yesterday after the match, I felt that something happened in the knee," Nadal said, quoted on the official ATP website.
"I wanted to try my best to be competitive today. I warmed up today in the morning and I felt that my knee was not good enough to compete at the level that I need to compete, to play the semi-finals of this event."
The world number two added: "For me it is not about today only. It's about what it means for me to have to pull out in a tournament that I love so much like this one, and in the semi-finals after playing well during the whole tournament.
"You can imagine that I can't be happy. So that's all. Sometimes it is tough and can be frustrating for me personally to go through all this stuff."
Federer is looking to follow up his 100th title in Dubai last month, and had come through his quarter-final with a straightforward 6-4 6-4 win over young Pole Hubert Hurkacz.