They found themselves down 23-7 just before halftime in front of a 27,000-strong capacity crowd at Prince Chichibu Memorial Stadium in Tokyo on Friday night, but kept the home side scoreless in the second half to surge back to win 29-23.
TJ Perenara, Ben Lam, Chase Tiatia and Wes Goosen scored their four tries, with the latter three coming in a 19-minute spell through the middle stages of the second half.
While they got the win, it was a performance riddled with a plethora of errors - they conceded 16 turnovers by the time all was said and done.