Lee Zii Jia conceded the Hylo Open men's singles title through a lower back injury in the third game to hand Loh Kean Yew the victory in Germany.
Loh's victory read 19-21, 21-13, 17-12 after 64 minutes as the Lee failed to add to his All-England title won in March.
It was the Malaysian who got off to a good start against Loh, who was the last shuttler to beat him at the French Open opening round last week.
Lee raised the tempo from the offset with an expected attacking display to lead 11-7 at the interval.
Loh deserved a lot of credit for putting the graft to stay in the game and push the Malaysian all the way, at one stage only trailing 17-18.
But Lee showed strong combative mental strength to power home to a 21-19 lead.
The second game started well enough for Lee who held a four point advantage at 9-5, but a dogged Loh battled back to 9-9 before Lee again found the extra mile for a 11-9 lead.
But the second half of the second game belonged completely to the Singaporean, who asked all the right questions to steamroll his way to a 21-13 victory over an error-strewn Lee.
The deciding game was neck-and-neck with neither willing to wilt as Loh seized the advantage with a 11-10 lead, as Lee looked to struggle with his lower back as he landed upon smashing.
Loh eventually sealed the title after leading 17-12 as Lee eventually retired for an anti-climax ending.