Top seed Roger Federer beat German Philipp Kohlschreiber 7-5 6-3 in the quarter-finals of the Gerry Weber Open in Halle.
Swiss to face German Petzschner in the semi-finals
Roger Federer remains on course for a sixth Gerry Weber Open title after seeing off Philipp Kohlschreiber 7-5 6-3 in the quarter-finals.
The world number two extended his unbeaten run at Halle to 28 matches by defeating his German opponent in just 68 minutes.
Kohlschreiber had wasted an early break-point opportunity and was level with the top seed at 5-5 in the opening set before losing five games on the bounce.
Federer, who has won the tournament on his last five visits, duly completed a routine victory on his first match point, setting up a semi-final clash with another German in Philipp Petzschner.
Not easy
"That is not going to be easy. Philipp has played really well here and I have watched him, but we have not played each other yet," Federer said.
Petzschner booked his place in the last four by beating Slovakian Lukas Lacko 6-4 6-3.
Lleyton Hewitt secured a spot in the other semi-final with a 7-6 (7-0) 6-1 result against Andreas Beck - his 96th career win on grass.
The Australian, seeded eighth, hit 13 aces to get past the German wild card.
Next up for the former world number one will be Benjamin Becker, who dropped just eight points as he beat fellow German Mischa Zverev 7-6 (7-4) 6-0.
