Madrid - Tomas Berdych mastered the slick blue clay to topple Argentine Juan Martin del Potro 7-6 (7/5), 7-6 (8/6) on Saturday and reach the final of the Madrid Masters.
The sixth-seeded Czech will bid for his eighth career title - and second at the Masters 1000 level - on Sunday when he plays either third seed Roger Federer or Serbian number seven Janko Tipsarevic.
Berdych fired down 15 aces in a contest lasting just over two and a quarter hours at the Caja Magica.
"He was my toughest match of the week," said the winner. I had that feeling from the start. But I was confident going in. I had my belief.
"I'm definitely happy with my the game that I've played here all week."
The Czech won only his second match out of five against Del Potro, who captured the Estoril title last weekend, as he began his campaign for the French Open later than most of his rivals after resting at home.
Coming to the court, Berdych had won 26 service games this week and got one more before finally being broken in the third game of the opening set.
But he took it back in the 10th game for 5-5 as Del Potro was broken while serving for the set.
The distraught Argentine rallied from 1-5 down in the tiebreaker but still lost it after 68 minutes.
Berdych began the second with a break, was broken back for 3-3, but again showed his nerve with a winning tiebreak effort to advance into the title match on a second match point after Del Potro saved the first with an ace.
Del Potro dropped to 10-1 on clay this season and 22-2 on sets after defeating Berdych in their last three meetings without losing a set.
"I lost because Berdych played better, and that's the only reason," said Del Potro, who disputed several line calls and did not shake hands with the chair umpire at the end of the match.
Berdych will be playing in his 14th ATP World Tour final and third Masters final, having won in Paris seven years ago before losing in Miami in 2010.