Top seed Alexander Zverev crashed out of the Shenzhen Open as his recent dip in form continued.
The German, up to a career high fourth in the world rankings, needed three sets to beat Steve Darcis on Thursday, but he was unable to shake off the rust as in-form Dzumhur won 6-4 7-5 to book his place in the last four.
After a brilliant season that has seen him claim two Masters titles as part of a five-tournament haul this season, Zverev has stuttered since beating Roger Federer to the Rogers Cup title in Montreal.
He was beaten by Frances Tiafoe in the second round in Cincinnati before a second-round defeat to Borna Coric at the US Open, and on his return to action his struggles were evident in China as the season heads into it’s final straight.
The 20-year-old is seen by many as a future no 1 but his exertions over the first half of the season look to be taking their toll on the German, who has already qualified for the NextGen Finals and looks certain to make his World Tour Finals debut – sitting behind only Federer and Rafael Nadal in the Race to London standings.
Dzumhur meanwhile is heading in the opposite direction. Having become the first Bosnian to claim an ATP-level title with victory over Fabio Fognini in St Petersburg, his win over Zverev takes his recent run to eight successive wins – going further back he has won 18 of his last 21 matches on the ATP Tour.
The 25-year-old is up to a career high 40th in the world and will next face Alexandr Dolgopolov after the Ukrainian’s opponent Dudi Sela was forced to withdraw injury from their quarter-final match.
In the bottom half of the draw, second seed David Goffin raced past Donald Young to reach the last four where he will face world no 107 Henri Laaksonen, who ended the run of Chinese qualifier and world no 495 Zhinzhen Zhang with a 6-4 3-6 6-2 victory.
