Struff was one of two home favourites to be defeated on Thursday afternoon. He lost out to the entertaining Kazakh 3-6 7-6, 3-6 in the end who powered 43 winners including 23 aces in a superb serving display.
He advances to his second tour-level Quarter-Final of the season at the expense of Struff.
While another German home hero was also downed in the last match of the evening as Yannick Hanfmann was defeated by Andrey Rublev.
Rublev hasn't had the best of times in recent months with this being his first Quarter-Final in two months despite sealing his first Masters title earlier on this season.
But he is now missing a grass court title and will look to further that ambition this week. He defeated Hanfmann 7-6(6), 6-3.
Also through is Jannik Sinner who saw off Lorenzo Sonego earlier today and will now face Alexander Bublik in the Quarter-Finals.
Rublev will face the winner of Tallon Griekspoor and defending champion, Hubert Hurkacz, with Alexander Zverev - Nicolas Jarry and Daniil Medvedev - Roberto Bautista Agut also set for tomorrow.
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Second quarter-final of the season ✌️
Alexander Bublik sets up a showdown with Sinner, fighting past home favourite Struff, 6-3, 6-7(4), 6-3!
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