Five-time winner Roger Federer outclassed Germany's Mischa Zverev 6-0, 6-0 on Friday to book his place in the semi-finals of the Halle Open.
The world number three will now face Tommy Haas, who beat him in last year's final, after the veteran German saw off France's Gael Monfils 6-7 (4/7), 6-3, 6-3.
The 31-year-old Federer wrapped up the match against the world number 156 in just 39 minutes.
"You never go on to court aiming for such a score. I'm surprised to have managed it today," said Federer, who earned just the second "double bagel" whitewash of his career.
His first was inflicted on Argentina's Gaston Gaudio in the semi-final of the Shanghai indoor tournament on November 14, 2005.
In Halle, the Swiss was even more efficient than in his opening 6-3, 6-3 victory over another German qualifier, world number 166 Cedrik-Marcel Stebe, in 67 minutes.
"I expect a completely different opponent (in Haas) tomorrow (Saturday). (Having played just two hours over two matches) could be an advantage as well as a disadvantage," said Federer.
"I see it as above all the opportunity to play for a place in the final and then for the title."
Federer, who has won a record 17 Grand Slams, is still out to win his first trophy of the season and now has 41 wins and just five defeats on the grass at Halle.
France's Richard Gasquet, the world number nine, went through to the semi-final with a 6-3, 7-6 (7/4) victory over German world number 33 Florian Mayer.
Gasquet will meet the winner of the match between Germany's Philipp Kohlschreiber and Russian Mikhail Youzhny.
The Frenchman's victory was revenge after Mayer beat him in the Wimbledon quarter-final last year.
"I played very well against an opponent who I know can be dangerous," said Gasquet.
He won the first set with ease in 34 minutes but was forced to a tie-break in the second, eventually winning out with an ace.
His advance to the last four is the fourth time this year he has made a semi-final. He was beaten by Andy Murray in Madrid but won the other two on the way to titles in Doha and Montpellier.