Top seed Roger Federer continued his flawless record at this year's Wimbledon as he beat Germany's Jan-Lennard Struff in another routine win.
The defending champion and eight-time winner needed one hour and 34 minutes to win 6-3 7-5 6-2 on Centre Court.
The Swiss great has not dropped a set in his three matches so far, extending his winning streak to 29 in a row.
Federer, 36, will play French 22nd seed Adrian Mannarino, who beat Russian Daniil Medvedev, in the last 16.
The 20-time Grand Slam champion is bidding for a joint-record ninth singles title at SW19, which would see him draw level with Martina Navratilova.