French tennis player Gael Monfils didn't have a memorable campaign at this year's ATP Munich. The Frenchman lost his opening match of the tournament on Thursday. Monfils, who had a first-round bye, was ousted by unseeded Hyeon Chung. South Korean Chung handed a loss to the top-seed of event in a two-set battle 6-2 6-4. World number 78 Chung converted 3-of-9 of his break point chances in the match, while saving all three of Monfils' break point tries. It took an hour and 12 minutes for the clash to conclude. Chung now has a 1-0 head-to-head record over 30-year-old Monfils.

The match on Thursday was the first-ever meeting between the two players.

Hoping to shake off the rust

Prior to this week's Atp Munich, Gael Monfils had not played a match in almost two months. The Frenchman took a break to heal a leg injury after a round-of-16 loss suffered against Austria's Dominic Thiem at the Indian Wells Masters.

The pause certainly affected the 30-year-old's performance against Hyeon Chung. How he will play now that he has come back from said injury remains to be seen.

Guido Pella stuns the number four seed

Fourth-seeded Fabio Fognini had his ATP Munich campaign finished on Thursday. The Italian tennis player was stunned by qualifier Guido Pella in the round-of-16 stage.

Argentina's Pella lost just five games on his way to defeating the Italian 6-3 6-2. Pella won 28-of-34 of his first serve points in an hour and six minutes of play. He broke Fognini five times in seven attempts while losing his service twice to the number four seed. The head-to-head record between Pella and Fognini sees the Argentine having a 2-1 record at the ATP level over the Italian.

No back-to-back titles

2016 ATP Munich champion Philipp Kohlschreiber failed to repeat last year's success achieved in Munich. Horacio Zeballos of Argentina handed a loss to Kohlschreiber to crush the German's hopes of winning back-to-back titles in Munich. The unseeded player outclassed the fifth-seed from Germany in a two-set battle 7-6 (7-5) 6-4.

Zeballos fired eight aces and broke the service of Kohlschreiber once during the match. The 2016 Munich champion had three break point chances in the match, but didn't convert any of them in an hour and 38 minutes of action. Next up for Zeballos will be world number 158, Pella.

Another seed out

Martin Klizan beat sixth-seeded Mischa Zverev in the last singles match of the day in Munich. The Czech lost just three games to the seeded German in 49 minutes spent on the court 6-2 6-1. Klizan won 22-of-25 of the points played behind his first serve while converting 4-of-7 of his break point opportunities. 27-year-old Klizan is now set to face Hyeon Chung in the ATP Munich quarter-final on Friday.