Richard Krajicek conceded only nine points on his own serve in his 6- 4, 6-3 win against David Prinosil in the quarter-finals of the Japan Open on Thursday.
The top seed, who served nine aces, said: "Any time I needed a big serve, I got it."
In the semi-final, Krajicek faces Patrick Rafter, the No 6 seed, who beat his fellow Australian, Todd Woodbridge, 6-4, 7-6.
Krajicek broke Prinosil in the first game of each set. On his own serve, he lost the first point and did not lose another until the first set's last game.
"If I keep playing like this, I think I have a very good chance of winning here," said Krajicek, the 1996 Wimbledon champion who is now ranked sixth in the world.
Prinosil said: "Today was very difficult, very windy. It's hard to play Richard if he breaks you in the first game."
Sweden's Thomas Johansson, who now has a 16-1 match record and two tournament titles since 10 March, beat Mark Woodforde, also of Australia, 6-3, 6- 4. His semi-final opponent will be Lionel Roux, of France, who beat Boris Becker in the third round and then Martin Damm, of the Czech Republic, 6-3, 6-1 in the quarter-final.
The wind worsened for the Rafter-Woodbridge match when Rafter came back from 40-0 to break in the second set's first game and took a 2-0 lead. After a time out to fix one of the singles poles and chase down the ballboys' kneeling mats, blown away by the wind, he lost nine straight points and was even at 2-2. He broke again in the fifth game but was broken back in the 10th. In the tiebreak, he won four straight points from 3-3 on errors by Woodbridge.
The frustrations continued for Woodbridge and Woodforde, the world's top-ranked doubles pair when they lost their quarter-final 6-3, 6-7, 7- 6 to Rafter and Justin Gimelstob.
America's Amy Frazier advanced to her fourth straight Japan Open women's final by overpowering Australia's Annabel Ellwood 6-2, 6-3. On Sunday Frazier will meet the winner of today's semi-final between Kimberly Po, of the United States, and Japan's Ai Sugiyama.
Frazier, the winner of the tournament in 1995, is a close friend of Po, her doubles partner and frequent practice partner.