Winger Josh Adams scored twice as Wales beat Japan 28-21 on Saturday to claim their second win of the inaugural Nations Championship.
Adams crossed either side of the interval with prop Archie Griffin and fellow winger Louis Rees-Zammit also on the scoreboard.
Wales entertain New Zealand next weekend eyeing an unlikely first victory over the All Blacks since 1953.
They overcame Fiji in July before losses to Argentina and South Africa.
Eddie Jones's Japan remain on just one success from four fixtures in the tournament.
Replacement scrumhalf Kenta Fukuda's 75th minute effort caused Wales a late scare but was only enough to secure a losing bonus point.
The Brave Blossoms head to England next Saturday.
Wales head coach Steve Tandy started with physical pair Eddie James and Max Llewellyn in midfield, prioritising power over the playmaking ability of Ben Thomas.
Australian Jones made five changes from the defeat to Fiji two weeks ago, including handing fly-half Riku Kitahara a test debut.
The meeting came 12 months on from Wales ending a two-year wait for a home test win by edging Japan by a point, and denying the Brave Blossoms a first victory in Cardiff.
A sparse crowd was present at the Millennium Stadium, underlining the negative atmosphere surrounding Welsh rugby due to poor results from the test team and the threat of losing one of the country's four professional sides.
Wales took the lead three times during the first half, first through Griffin and then the 31-year-old Adams.
But Japan hit back through Ben Gunter and Warner Dearns.
Rees-Zammit stepped over moments ahead of the break for his first test try in a year.
Adams's match-winning second try came with 11 minutes to go after a superb break from deep by full-back Blair Murray, and a final pass from influential scrum-half Tomos Williams, who had also set up Griffin early on.
With seconds left on the clock, Adams showed his defensive ability, claiming a turnover penalty to make sure of the victory for just a fourth win in Tandy's 13 tests in charge.