On a cold day in Munich, German star Alexander Zverev tumbled out of the event falling to Christopher O’Connell 7-6(7-2), 6-4.

Zverev, a 2-time Munich champion, had nice aces with five doubles, but won just 41% on second serve. He’ll now head to Madrid, a event he’s also won twice.

TOp seed Holger Rune ousted Zverev’s countryman Yannick Hanfmann 6-3, 6-4.

The 9th-ranked Rune tossed in four doubles, lost only seven points on first serve and dropped serve just once. Rune broke serve early in both sets to pace the comfortable win.

“It was a tough match,” Rune said to the ATP. “I am happy with the way I played. It is difficult to play the first match, different conditions. Thank you guys for the support. I really love this tournament. I had made my breakthrough with my first title here last year, so it is special to be back.”

No. 2 Taylor Fritz advanced past Marton Fucsovics 4-6, 6-3, 6-3. The American broke for 5-3 then served it out for a spot in the quarters.

Fritz will await the suspended Thiem-Huesler match.

Also on Thursday, No. 4 Botic Van De Zandschulp had an easy victory over former Australian Open semifinalist Aslan Karatsev 6-2, 6-0.Cristian Garin of Chile surprised (27y,45r) 6th-seeded Lorenzo Sonego in straight sets 6-3, 7-6(7-3). Marcos Giron of the United States beat Switzerland’s Alexander Ritschard 4-6, 6-3, 6-3. And Italy’s Flavio Cobolli overcame Oscar Otte of Germany in three 6-0, 3-6, 6-3.

On tap Friday, matches slated in quarterfinals play are highlighted by Rune taking on Garin. Rune is a perfect 2-0 against the Chilean with a win last fall in Stockholm.

Van De Zandschulp locks up with Giron with Giron having won both meetings.

Flavio Cobolli squares off against Christopher OConnell and in a first-time tour-level battle.