Defending champion Alexander Zverev moved a step closer to reaching the final of the Munich Open on Wednesday, as rising star Frances Tiafoe ousted Gilles Muller in Estoril.
Zverev wasted two set points in a lengthy first-set tie-break before overcoming Yannick Hanfmann 6-7 (12-14) 6-4 6-2.
Up next for the holder at the ATP 250 event in Munich will be another German opponent, Jan-Lennard Struff having beaten Yannick Maden in three sets.
Hyeon Chung, the fourth seed, is on course to meet Zverev in the semi-finals, should the impressive young Korean get the better of Martin Klizan.
Chung brushed aside Matthias Bachinger 6-1 6-1, while Klizan, Novak Djokovic’s recent conqueror in Barcelona, had to come from a set down to beat Mirza Basic.
READ | Off-form Novak Djokovic says he’ll work hard to restore confidence
American Tiafoe defeated world number 28 Muller, the fourth seed and last year’s beaten finalist, 6-4 7-5 at the Estoril Open.
Joao Sousa won an all-Portuguese showdown with Pedro Sousa 4-6 7-6 (7-1) 7-5, while third seed Kyle Edmund saw off young Australian wildcard Alex de Minaur and Simone Bolelli edged out Federico Delbonis.
{{/usCountry}}Joao Sousa won an all-Portuguese showdown with Pedro Sousa 4-6 7-6 (7-1) 7-5, while third seed Kyle Edmund saw off young Australian wildcard Alex de Minaur and Simone Bolelli edged out Federico Delbonis.
{{/usCountry}}Laslo Djere sprung one of several surprises at the Istanbul Open, beating third seed Andreas Seppi 6-3 6-7 (4-7) 6-3.
Rogerio Dutra Silva and Taro Daniel also defeated higher-ranked opponents, accounting for sixth seed Viktor Troicki and fourth seed Aljaz Bedene respectively.
Marco Trungelliti could not follow suit, though, fifth seed Paolo Lorenzi winning their match 6-2 7-6 (7-5).