Svetlana Kuznetsova toppled world number three Karolina Pliskova 7-6 (7/5), 7-6 (7/2) on Friday to book an all-Russian Indian Wells final against Elena Vesnina.
Vesnina powered past France's Kristina Mladenovic 6-3, 6-4, continuing a sparkling campaign that has seen her shock German's soon-to-be world number one Angelique Kerber in the fourth round and seven-time Grand Slam champion Venus Williams in the quarter-finals.
It's a sharp turnaround from Vesnina's first-round ouster in qualifying here last year, and marks her first trip to a final of one of the WTA's elite Premier Mandatory events.
World number eight Kuznetsova is back in the Indian Wells final for the first time since back-to-back runner-up finishes in 2007 and 2008.
She withstood 10 aces from Pliskova, who has already won titles at Brisbane and Doha this year.
"I tried my best to fight every point," said the 31-year-old Kuznetsova, owner of two Grand slam singles titles who enjoyed a resurgence in 2016, winning two titles as she returned to the top 10 in the world for the first time since 2010. "Karolina is one of the best players this year."
After falling behind 5-3, the Czech made Kuznetsova work to close out the opening set, saving a set point in the ninth game and four more in the tiebreaker after Kuznetsova seized a 6-2 lead in the decider.
A double fault left Kuznetsova with one more chance at 6-5, and she grabbed it with a forehand passing shot.
After an exchange of breaks in the second they went to the tiebreaker, where Kuznetsova again took a 6-2 lead and the increasingly frustrated Pliskova surrendered with a string of errors.
- Vesnina 'too good' -
Vesnina, a Wimbledon semi-finalist last year who has reached a career high of 15th in the world at the age of 30, said important doubles wins -- including a gold medal at the 2016 Rio Olympics -- had helped her big-match composure.
"It's not easy to hold your nerve," she said. "But I'm really happy the way I handled it. I was very focused. I was not thinking about the final. I was just thinking particularly about every single game, every single shot."
Vesnina built commanding leads in each set -- 5-0 in the first and 5-1 in the second.
Mladenovic, who claimed a maiden WTA title in St. Petersburg last month before reaching the final in Acapulco, couldn't find an answer no matter how she tried.
"I really think she was just too good for me today," said Mladenovic, who went to her slice to no avail before attempting an aggressive serve and volley game late in each set in an bid to regain ground.
"I felt like I had to do kind of crazy points to win," Mladenovic said. "She didn't really allow me to put my game on tonight."
Down a set and three service breaks at 5-1 in the second set, Mladenovic won three straight games -- fending off one match point -- before Vesnina held serve for the victory.
"Kiki was always trying to play her best tennis when she was behind on the score," Vesnina said. "It's not easy to come back from 5-0 and 5-1. It's not easy at all."