Roger Federer cruised past Mischa Zverev 6-0, 6-0 to reach the Gerry Weber Open semifinals on Friday, recording his second career "double bagel."
Richard Gasquet also made the last four, defeating Florian Mayer 6-3, 7-6 (4).
The third-ranked Federer needed only 39 minutes to defeat the 156th-ranked Zverev. Federer earned his first "double bagel" against Gaston Gaudio at the 2005 Masters Cup in Shanghai.
"It's not something which is easy to do. You never go into a match aiming for that score," Federer said. "I was very surprised that it happened today, especially on grass.
"I think it is disappointing for a serve and volley player to go down like this. It shows also how easy it is to hit passing shots or returns today."
Zverev, a German wild card, stuck to his game plan and paid for it.
"I hope he doesn't take it too badly," Federer said. "I just had a pretty easy time picking up his serve, and I must have made a ton of returns."
While noting he'd rather win 6-1, 6-2, Federer said it never crossed his mind to give Zverev a game. He said the only time he lost 6-0, 6-0 was his first match, at age 8.
Federer is aiming for his first title of the year. In the semifinals, he will play either Tommy Haas or Gael Monfils. Haas beat Federer in last year's final in Halle.
Mayer produced a pair of stunning diving winners, but Gasquet was the steadier player and served an ace to finish the match. Gasquet will play either Philipp Kohlschreiber or Mikhail Youzhny.
Federer is seeking his sixth title on the grass court at Halle, his favorite tuneup for Wimbledon. Federer owns seven Wimbledon titles and returns as the defending champion. Four of his Wimbledon titles have come after triumphs in Halle. His last title in Halle came in 2008.
"It's been a long time since I won here, so that title this year has the highest priority for me," said Federer, who holds a record 17 Grand Slam titles.