Britain's men missed out on the medals at the World Triathlon Championships in Hamburg on Sunday.
Unger proved the strongest in a tight finish
Will Clarke led the field during the run but was overhauled in the latter stages and came in fifth.
Stuart Hayes finished eighth, and Tim Don, the reigning world champion, could manage only a 10th-place finish.
Germany's Daniel Unger out-sprinted Spain's Javier Gomez to take the world title in front of his home crowd, with Brad Kahlefeldt of Australia in third.
Unger was a surprise winner in a time of one hour, 43 minutes, 18 seconds and his victory secures him a place at next year's Olympic Games in Beijing.
Hayes led the British out of the 1500m swim, with Don and Clarke in close contention, and the trio remained in the leading pack on the bike.
Don then hit the front at the start of the run before Clarke took over on lap two, leading by five seconds at one stage.
But the chasing pack of five reeled in the Briton, last year's World Under-23 Champion, and he came in 26 seconds behind Unger.
"I'm absolutely ecstatic with my race," said Clarke.
"I've shown I can compete with the best in the world and to finish top five at the senior world champs is much more satisfying than my World Under-23 win last year.
"The course at next year's Olympic Games in Beijing is much tougher on the bike and that will really suit me; I'm ready to challenge for the medals."