Kyle Edmund has fallen to defeat in his first appearance in a challenger final by losing in straight sets to John Millman in Yokohama.
The 19-year-old had defeated the experienced Go Soeda in the last four, but he could not find one final push against the in-form Australian.
Millman, who beat Edmund and James Ward to win in Traralgon last week, broke the British number five once in each set to claim a 6-4 6-4 triumph.
Despite the setback, Edmund will become British number four when the ATP world rankings are updated on Monday, while he will also break into the top 200 for the first time in his professional career.