Wimbledon champion Elena Rybakina, who is seeking to become the fifth woman to win back up the Indian Wells title with the Miami crown, came through two rollercoaster sets and a couple of rain delays to beat Jessica Pegula 7-6(3) 6-4 in their semi-final.
Neither player was able to settle into their serve but Moscow-born Rybakina, who now represents Khazakhstan, came out on top in a tense tiebreak before edging the second set to record her 13th straight win.
"I was playing much better when I was down," Rybakina said on court after her first win over Pegula in three meetings. "First set was very tough. The tie-break could go both ways."
Rybakina's opponent in the final will be either twice Wimbledon champion Petra Kvitova, who beat Russia's Ekaterina Alexandrova 6-4 3-6 6-3, or unseeded Romanian Sorana Cirstea.
Earlier on Thursday, Medvedev ended the dream run of American qualifier Christopher Eubanks with an impressive 6-3 7-5 victory in a rain-interrupted match to reach the semi-finals of the tournament for the first time.
The fourth-seeded Russian trailed 3-2 in the first set before rain stopped play but when the match resumed 30 minutes later he was a man on a mission, winning the next five games and never trailed again.
{{/usCountry}}The fourth-seeded Russian trailed 3-2 in the first set before rain stopped play but when the match resumed 30 minutes later he was a man on a mission, winning the next five games and never trailed again.
{{/usCountry}}Medvedev broke Eubanks for a fourth time to seal the win on his third match point when the American sent a forehand smash wide as the red-hot Russian prevailed 6-3 7-5 and has now won 22 of his past 23 matches.
"I didn't play my best before (the rain delay). The rain helped me go out and have more energy," said Medvedev. "It helped me and I only played better and better, apart from one bad game on my serve, but it happens."
Medvedev will next face fellow Russian Karen Khachanov, who advanced with a 6-3 6-2 win over Argentine Francisco Cerundolo.
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