Roger Federer has progressed through to the semi-finals in Halle after whitewashing Mischa Zverev.
The world number three, who required just 39 minutes to seal the comprehensive 6-0 6-0 win, will now play either Tommy Haas or Gael Monfils in the last four.
The Swiss player was dominant from start to finish, allowing Zverev just seven points on his own service games during the first set.
The pattern continued in the second, with Federer finishing the match having conceded just 22 points during 12 games.
