Tomas Berdych reached the final of a Masters event for only the third time when he edged out Juan Martin Del Potro 7-6 7-6 in a gripping claycourt slugfest at the Madrid Open overnight.
He will play third seed Roger Federer of Switzerland or seventh-seeded Serb Janko Tipsarevic, who stunned world number one and compatriot Novak Djokovic in the quarter-finals, in Sunday's title match.
Djokovic and great rival Rafa Nadal have slammed organisers over the introduction of blue clay for this year's edition, which they say creates a dangerously slick surface, and both have threatened not to return next year unless the traditional red dirt is reinstated.
Nadal was beaten in the third round by Fernando Verdasco, his first loss to his Spanish compatriot in 14 meetings and his first defeat on clay in 23 matches.