(CNN) -- If this is an indication of what Roger Federer will do at Wimbledon, his opponents had better watch out.
Federer recorded the second double bagel of his career when he defeated wildcard Mischa Zverev 6-0 6-0 on Friday to reach the semifinals of a Wimbledon warm-up in Halle, Germany.
The only other time Federer didn't drop a game in a match was at the year-end championships in 2005 against clay-court specialist Gaston Gaudio.
"You never go to court aiming for such a score," Federer, who turns 32 in August, told reporters. "I'm surprised to have managed it today."
At Wimbledon, which begins on June 24, Federer will be bidding to advance to a first grand slam final since claiming a seventh title on the Wimbledon grass a year ago.
He lost to Tomas Berdych in the U.S. Open quarterfinals last September, Andy Murray in January's Australian Open semifinals and Jo-Wilfried Tsonga in this month's French Open quarterfinals.
Federer knows the chances of registering a second consecutive double bagel are slim. He meets local favorite and the man who beat him in last year's final in Halle, Tommy Haas, in the last four.
"I expect a completely different opponent tomorrow," Federer said.
Haas and Federer, good friends, played doubles together this week in Halle.
"He is one of the greatest of all time, perhaps the greatest," said Haas.
Haas, the 35-year-old third seed, rallied from a set down to oust Gael Monfils 6-7 (4) 6-3 6-3.
But he was the only German winner on the day. Besides Zverev, sixth-seed Philipp Kohlschreiber and eighth-seed Florian Mayer were also sent packing.
French second-seed Richard Gasquet topped Mayer 6-3 7-6 (4) and Russian Mikhail Youzhny beat Kohlschreiber, the 2011 champion, 6-3 6-2.
At Queen's Club in London, the other men's warm-up taking place this week, top-seed Andy Murray progressed to the semifinals with a 6-4 7-6 (3) victory over Germany's Benjamin Becker.
The Scot returned from a back injury at Queen's and hasn't lost a set in his three matches, despite several stops and starts due to rain. He has shared the spotlight at Queen's with veteran and four-time winner Lleyton Hewitt.
"I thought the first set was good, and then he started playing much better in the second," Murray said in a televised interview. "I just managed to hang tough and get the win. The conditions were tough, again, but it's only my first week on grass."
While Federer tries for an eighth success at Wimbledon, Murray will attempt to end a 77-year British men's singles drought at the All England Club.
His next foe is fourth-seed Tsonga, who suffered a painful semifinal defeat to David Ferrer on home soil at the French Open.
Tsonga eased past young American Denis Kudla 6-3 6-2.
Hewitt, who has endured multiple hip operations, toppled Juan Martin del Potro 6-2, 2-6, 6-2. Del Potro, still learning the finer points of playing on grass, missed the French Open due to illness.
"I'm still hanging in there," the 32-year-old Hewitt said. "The last four or five years have been tough with surgeries, but mentally I feel fresh."
As in Halle a back-to-back winner remains a possibility because Croatian Marin Cilic, the fifth seed, edged Berdych 7-5 7-6 (4).
Cilic almost exited in the third round, trailing Feliciano Lopez 5-2 in the third set before staging a comeback.