The top seed required just 40 minutes to beat Mischa Zverev at the Gerry Weber Open in Halle.
“It’s not something that is easy to do. You never anyway go into a match aiming for that score,” Federer said. “Eventually you start feeling that there is an opportunity maybe and even then it’s not what you really want to think about because at the end of the day you just want to win the match and not start thinking too far ahead and then it comes back and gets you. I was very surprised today that it happened, especially on the grass.”
Federer, 31, has played 1,107 tour-level matches (902-205) since turning professional in 1998. He also beat Gaston Gaudio 6-0, 6-0 at the 2005 Tennis Masters Cup in Shanghai (now known as the Barclays ATP World Tour Finals).
The Swiss is making his 11th appearance at the ATP World Tour 250 grass-court tournament in Halle (41-5 record). He has won five titles from seven finals.