MUNICH — Alexander Zverev began his Munich Open title defense with a 6-7 (12), 6-4, 6-2 win over Yannick Hanfmann on Wednesday.

The top-seeded Zverev needed over two hours to prevail over the 118th-ranked Hanfmann, a wild-card entry, and set up a quarterfinal against Jan-Lennard Struff.

Struff defeated German compatriot Yannick Maden 6-3, 3-6, 6-3.

The fourth-seeded Chung Hyeon progressed with a 6-1, 6-1 second-round win over Matthias Bachinger and will next face 2014 tournament-winner Martin Klizan.

Klizan defeated Mirza Basic of Bosnia-Herzegovina 4-6, 6-3, 7-5 earlier Wednesday.