Yet, the 23-year-old could very well have added another scalp to his list this week after he reeled off seven games in a row to fight back from a set down to level the match and go a break up in the decider.
However, the momentum swung back in Dzumhur’s favour with a break to love in game four of the third set, and he broke again in the 10th game to set up a semi-final date with Jan-Lennard Struff after the German beat Jo-Wilfried Tsonga in three sets.
Second seed Tsonga took the first set 6-3, but world number 54 Struff bounced back to take the second 6-3 before clinching the decider 6-2.
Highlights: Struff shocks Tsonga
Elsewhere, top seed Roberto Bautista-Agut made light work of Viktor Troicki - the Spaniard won 6-1 6-2 to reach the last four.
Highlights: Bautista Agut beats Troicki in straight sets to reach semi-finals
Bautista-Agut will face Fabio Fognini for a place in the final after the Italian demolised Ricardas Berankis 6-3 6-0 in just 58 minutes.