Tokyo - Australian star Ian Thorpe's Asia World Cup series ended in the morning heats in Tokyo on Sunday when he finished 26th overall in the men's 100 metre butterfly.
The five-time Olympic gold medallist clocked 53.59 seconds, far behind top finisher Takeshi Matsuda of Japan in 51.39, failing to qualify for the final.
The Japanese duo of Ryo Takayasu and Kazuya Kaneda followed Matsuda in 51.40 and 51.63, respectively.
"This week has been challenging, but has been very good," said Thorpe. "I wish I could have done it with no one watching but that's unfortunately not the case. I am very comfortable with where I'm at."
On Saturday, Thorpe also failed to qualify for the final of the men's 100m freestyle after finishing 12th with 49.45. He then pulled out of the 100m individual medley, citing a poor physical condition.
Thorpe's exit marked a disappointing return to action for the former Olympic champion ahead of Australia's Olympic trials in March where he will bid to qualify for London 2012.