Halle: Roger Federer beat Belgium`s David Goffin 6-1, 7-6 (12/10) on Friday to reach the ATP Halle grass court semi-finals and move to within one win of an 11th appearance in the final.
The Swiss world number three, a 17-time Grand Slam winner, is seeking a ninth title in the Wimbledon warm-up event and fourth in succession at the tournament.
Top seed Federer will play Alexander Zverev in Saturday`s last four after the young German, 19, beat Cypriot Marcos Baghdatis 7-6 (11/9), 6-3.
"I thought Zverev played well. He played a crucial huge first set," Federer said.
"Marcos should have won that but ended up losing it, the momentum goes Zverev`s way, one break and the match is over. So credit to Zverev for getting the job done.
"He`s got a big serve, he`s got a nice backhand, he`s improving his forehand and he`s moving forward. He`s going to be a tough player in the future, no doubt about it."
Federer won their lone career meeting so far, 6-3, 7-5 at last month`s Rome Masters.
Zverev recorded his 26th match win in a career-best year to knock out 2007 runner-up Baghdatis.
"For me it doesn`t really matter what surface it is," said the teenager.
"It depends more on me, how I play, how I feel. I`ve played well on all four surfaces. I`ve played well on clay, I`ve played well on hard at the beginning of the year."
Austria`s Dominic Thiem, the third seed, is also through to the semi-finals after German Philipp Kohlschreiber pulled out of their quarter-final with a hip injury.