Edmund, third seed at the hard court tournament, nearly went a break up in the fifth game of the first set but his Japanese opponent saved two break points.
The remainder of the set also followed serve.
Image credit: PA Sport
Edmund's losing run continues in Cologne
Edmund broke twice during the tiebreak but failed to convert two set points and Uchiyama, ranked 185 in the world, won four points in a row to take the set in just under an hour.
Uchiyama wrapped up the second set in 36 minutes, claiming a spot in the next round after converting his second match point.
The damage was done in the third game, where Edmund was broken to love as Uchiyama took the match 7-6 (8/6) 6-4.
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