Qualifier Anna Kalinskaya stunned world number one Iga Swiatek to reach the Dubai Tennis Championships final.
Kalinskaya, 25, took one hour and 42 minutes to seal a 6-4 6-4 win against the four-time Grand Slam champion.
“I knew if I didn’t stay calm and aggressive, she would destroy me,” said Kalinskaya.
The Russian faces Italy’s Jasmine Paolini, who beat Romania’s Sorana Cirstea 6-2 7-6 (8-6), in Saturday’s final.
“I’m happy I got to play against her and I’m sure we’ll see a lot of each other in the future,” added Kalinskaya.
The world number 40 is the sixth-lowest ranked player to reach the final in Dubai and is the first qualifier to achieve that feat.
It is just a second loss in 26 matches for Swiatek, 22, after she won the Qatar Open title last week.
“I didn’t have power any more to give even more, which doesn’t happen often,” said Swiatek.
“I just felt out of control a little bit because of that. Usually when I tell myself what to do, I can improve my game. Today I was so out of power and tired that I just couldn’t.”
Kalinskaya beat world number nine Jelena Ostapenko and world number three Coco Gauff prior to her meeting with Swiatek.
Finalists Kalinskaya and Paolini met at the Australian Open in January, with the former winning 6-4 6-2 in Melbourne.
The pair are both set to feature in their first WTA 1,000 final when they meet in Dubai.