World number 10 Petra Kvitova extended her winning run by beating fellow Czech Karolina Pliskova to reach the Madrid Open final.
Both players began the match on a nine-match winning streak but Kvitova, 28, came through 7-6 (7-4) 6-3.
Two-time Wimbledon champion Kvitova, who won the Prague Open last week, is aiming to become the first woman to win the Madrid Open three times.
She will play Netherlands’ Kiki Bertens in Saturday’s final.
World number 20 Bertens beat French seventh seed Caroline Garcia 6-2 6-2 in her semi-final.
She has already knocked out world number two Caroline Wozniacki and five-time Grand Slam champion Maria Sharapova in Madrid.