Japan beat Italy 27-10 to make an impressive start to their Nations Championship campaign in Tokyo on Saturday, with coach Eddie Jones absent through suspension.
Japan fell behind but soon hit back against the Italians, who came into the game off the back of a successful Six Nations where they beat England for the first time.
Jones was barred from the stadium as he served the last game of his four-match suspension from the Japan Rugby Football Union for abusing match officials on a tour of Australia earlier this year.
Forwards coach Neal Hatley took his place and watched his side score two tries in the first half and one after the break in a confident performance in front of more than 20 000 fans.
Captain Warner Dearns, full-back Takuro Matsunaga and flanker Ben Gunter all got on the scoresheet for Japan, who started the match with uncapped university student Ryunosuke Ito at fly-half.
The home side looked like they could be in for a long evening when Italy's Juan Ignacio Brex burst through their defence to touch down for a try in the fifth minute.
But Japan responded just over five minutes later when Dearns lunged over the line for their first try.
Matsunaga added another midway through the first half when he finished off a slick passing move that sliced the Italian defence open.
An injury to full-back Lorenzo Pani gave the visitors further problems, and Matsunaga slotted a penalty to increase Japan's lead.
Italy spent the final moments of the first half camped out on the Japan line and kicked a penalty to reduce the deficit to seven points heading into the break.
But Japan stretched their lead seven minutes into the second half when Gunter touched down after a period of pressure.
Japan's Michael Leitch came off the bench to win his 93rd cap and gave a typically tenacious performance to protect his team's advantage.
Japan travel to Newcastle, Australia, to face Ireland in their next Nations Championship match, before returning to Tokyo to play France.
Italy will take on New Zealand in Wellington next weekend followed by Australia in Perth.