Tomas Berdych was the latest big-name casualty in the first round of the Gerry Weber Open when he was beaten by Marcos Baghdatis on Tuesday.
David Ferrer fell at the first hurdle at the hands of Andreas Seppi in Halle on Monday and Berdych made an early exit a day later, with Marcos Baghdatis inflicting a 7-6 (7-3) 7-6 (7-4) defeat on the fourth seed.
The world number eight and Baghdatis secured two breaks apiece, but it was the unseeded Cypriot who came out on top in the tie-breaks to move into round two of the grass-court tournament.
Seventh seed Viktor Troicki also bowed out on day two, going down 6-4 6-4 to highly-rated teenager Alexander Zverev.
Big things are expected of Zverev and the Hamburg-born 19-year-old grasped all three break-point opportunities, while failing to hold serve only once to move into the last 16.
Ivo Karlovic, beaten by defending champion Roger Federer in the semi-final of this tournament last year, blasted down 26 aces in a 7-6 (8-6) 6-3 victory over Andrey Kuznetsov.
Yuichi Sugita, Florian Mayer, Malek Jaziri and Dustin Brown were also first-round winners.