Japan's forwards produced a dynamic performance as rugby's Asian champions extended their record winning streak to 10 games with a nailbiting 26-23 victory over Italy in Tokyo.
New Zealand born Male Sau's bulldozing try on the hour mark ultimately proved the difference for Japan but the home side had to survive a nervous finish before recording their first win in six meetings with the Azzurri.
Japan are set to break into the world's top 10 for the first time, but coach Eddie Jones insists all that matters is next year's World Cup.
Japan are in Pool B at the World Cup in England, alongside South Africa, Scotland, Samoa and the United States.
They disappointed at the 2011 World Cup under former All Black John Kirwan, beaten by hosts New Zealand, France and Tonga before drawing with Canada.