Jan-Lennard Struff suffered a disappointing defeat on home soil to Laslo Djere at the Hamburg European Open on Tuesday.
Djere triumphed 6-4 7-5 against the seventh seed to book a last-16 tie against qualifier Thiago Seyboth Wild at the ATP 500 event.
It was a day of missed chances for world number 47 Struff, who took just one of eight break-point opportunities and hit five double faults as he went down in one hour and 50 minutes.
There was no such disappointment for Filip Krajinovic, though the sixth seed had to work hard before seeing off home wild card hope Daniel Altmaier 6-3 6-7 (3-7) 6-1.
Krajinovic will face another German next in the form of Philipp Kohlschreiber.
The number one seed Stefanos Tsitsipas is yet to start his campaign in Hamburg.
— ATP Tour (@atptour) July 13, 2021
In the Nordea Open, held in Bastad, there was a first-round defeat for teenage talent and sixth seed Lorenzo Musetti, who went down in three sets to Swiss qualifier Henri Laaksonen.