The German got off to a fast start to the match earning three breakpoints right away. Hurkacz was able to save all three and held serve to put the pressure back on Zverev.
The rest of the set remained on serve with a couple of breakpoints here on there on both players serve but each time they would be saved. At 5-4 with the 268th ranked German serving to stay in the match the number six seed had a set point and would make good on it sealing the first set 6-4 with a return winner down the line.
A tight finish :
The second set was almost the same as the first except this time it was the 31st ranked Pole who would have early breakpoints after holding his serve to start the set but the German was up to the task of saving them.
It went on serve until 2-1 when the Wroclaw native had another breakpoint and broke to a 3-1 lead when the Monte Carlo resident couldn't return a forehand. The German responded immediately breaking right back the very next game to put the set back on serve.
The very next game the Pole took back the lead as the 33-year-old German was struggling to hold serve and was broken once again. This time Hurkacz was able to hold and after Zverev held serve he would serve out the match to take it 6-4, and 6-3.
Hurkacz will now face the winner of the Gilles Simon vs Roberto Bautista Agut match in the quarter-finals.
Other matches :
Another busy day in Cologne even with no fans in attendance there was still lots of tennis to be played. Oscar Otte's magical run came to an end today as he fell to Radu Albot in three sets 6-4, 5-7, and 7-5.
Dennis Novak sent Benoit Paire packing in straight sets 6-3 and 6-4 and he will play the winner of Marin Cilic and Alejandro Davidovich Fokina match. Lloyd Harris continued his great run as he was able to beat American Steve Johnson in two tiebreaks 7-6 and 7-6 and will face the winner of the Fernando Verdasco Alexander Zverev match scheduled for tomorrow.