Berdych, the 2010 Wimbledon finalist, appears on course to claim his second Halle title following 2007 as he beat fifth-seeded Troicki 7-6 (3), 6-1 to reach the semis.

“I am finally feeling on the court how I would like to feel,” said Berdych, who needed just 1 hour and 21 minutes to beat the Serb. “It's still not 100 percent. But I am finally getting the right rhythm.

“I was quite confident from the beginning of the game that I could do well. So maybe that's why I looked calm.” Berdych fended off three break points in the early stages of the first set, which went to a tiebreaker. Berdych took two points off Troicki's serve for a 4-1 lead, which he did not give up.

Berdych broke Troicki in the fourth game for a 3-1 advantage and took a 5-1 cushion on a second break. Troicki fought off three match points in the next game before Berdych blasted a forehand winner on the fourth match point.

Berdych will next face unseeded German Philipp Petzschner, who beat eighth seeded Milos Raonic of Canada 6-3, 7-6 (6), 6-3.

Petzschner, the doubles Wimbledon champion from last year and semifinalist in Halle, broke Raonic's first service game in the first set and carried held his serve each time.

Petzschner failed to capitalize on a 5-2 lead in the second set tiebreaker as Raonic took two service points off the German in the tie break and won 8-6.

In the third set, Petzschner broke Raonic's first service game and jumped to a 3-0 lead. The local hopeful failed to convert three break points for a 5-1 lead but won when Raonic's backhand drop attempt went into the net after 1 hour 54 minutes.

World number eight, the third seeded Gaels Monfils also booked his spot in the final four, with a strong 6-4, 6-4 victory over German sixth seed and world number 18 Florian Mayer.

Each player broke in the first set before Monfils earned his second break in the 10th game to take the set 6-4.

Monfils broke the Mayer serve for a 4-2 lead in the second set only to see Mayer break right back. The Frenchman picked up a match point on Mayer's serve in the 10th game and finished the match in 1 hour and 4 minutes on a forehand down the line.

“I'm number eight in the world so this isn't really a surprise,” Monfils said. “I'm happy with the way I am playing on the grass. And this is great preparation for Wimbledon.” Monfils will take on another German in the semis, as unseeded 2008 Gerry Weber finalist Philipp Kohlschreiber beat defending champion Lleyton Hewitt of Australia, 7-6 (4), 6-3 in 1 hour and 30 minutes.

After both players held serve in the first set, Kohlschreiber picked up a mini break for a 4-2 lead in the tiebreaker and won it five points later.

Kohlschreiber secured the only break of the match in the eighth game for a 5-3 advantage and finished off Hewitt with an ace on his first match point.

“I don't know anything that really didn't work today,” Kohlschreiber said. “I'm happy that things just went well.

I couldn't really do anything wrong today.”