Shizuoka - Kenki Fukuoka struck the killer blow as hosts Japan stunned Ireland 19-12 on Saturday to take a giant step towards the Rugby World Cup quarter-finals with a breath-taking upset.

As it happened: Japan v Ireland

The replacement winger wriggled over on the hour mark to score the winning try of a frenetic Pool A clash as the Brave Blossoms added the "Shizuoka Shock" to the "Brighton Miracle" after toppling South Africa at the 2015 tournament.

Japan coach Jamie Joseph hinted that the result had not come as a surprise.

"You've just got to be careful before the game. You don't want to come across too arrogant and cocky," the ex-All Black said, praising his forward pack for holding Ireland in the set piece.

"We obviously had a lot of belief in our game plan and in what we wanted to do. We knew how good Ireland were and how strong they were."

Joseph added: "We're very proud of the players. We've been thinking about this game for quite a long time. Obviously Ireland were only thinking about it for the last six or seven days. But for us, it's been a great performance."

Ireland captain Rory Best said his team were not surprised how tough the game was.

"Anyone that is utterly shocked hasn't seen how good they are," the Irish hooker said.

"We were on the wrong side of the penalty count. But Japan played really, really well. They posed a lot of questions to us and unfortunately we couldn't come up with the right answers."

Ireland coach Joe Schmidt said he was "incredibly disappointed that we didn't manage to control the end of the game but they are a tremendous side, they did really well".

Ireland, who thrashed Scotland 27-3 in their opening game, had looked in control after first-half tries from Garry Ringrose and Rob Kearney.

But they went off the boil as Japan grew into the match, roared on by a partisan crowd of 47 000.

Fukuoka made the difference, darting over on the overlap to complete a stunning team try and put the home side in front - where they stayed, leaving Ireland's players slumped on the turf in disbelief.

Kotaro Matsushima, hat-trick hero of Japan's 30-10 win over Russia in last week's tournament curtain raiser, posed an early threat on as Japan edged a cagey opening.

Flyhalf Yu Tamura fluffed a makeable penalty, before Ireland took the lead after 13 minutes when the rampaging Ringrose rose brilliantly to snaffle Jack Carty's hanging kick into the corner.

Carty, stepping in for Ireland's talismanic playmaker Johnny Sexton, produced another moment of magic seven minutes later, dinking a clever chip that he managed to tip back to full-back Kearney to crash over.

Japan refused to buckle, however, and Tamura kept them in it with three clutch penalties.

Regular captain Michael Leitch's introduction after half an hour provided an instant impact, but Ireland survived to go into halftime up 12-9.

Tamura missed a three-pointer 14 minutes after the interval that would have tied the game.

But Japan's swarming pressure soon told, Fukuoka showing superb footwork to sneak over and give Japan the lead, triggering deafening cheers at Ecopa stadium.

Another Tamura penalty extended Japan's advantage to 19-12 with eight minutes remaining before Fukuoka effectively sealed the result with another tremendous burst that kept the ball in Irish territory until the final gong.

Ireland, who came into the tournament as the world's top-ranked team but have never won a World Cup knockout match, will look to bounce back against Russia.

Japan, whose target is a first-ever place in the last eight, know they still have no margin for error with games against Samoa and Scotland to come.

Teams:

Ireland

15 Rob Kearney, 14 Keith Earls, 13 Garry Ringrose, 12 Chris Farrell, 11 Jacob Stockdale, 10 Jack Carty, 9 Conor Murray, 8 CJ Stander, 7 Josh Van der Flier, 6 Peter O'Mahony, 5 James Ryan, 4 Iain Henderson, 3 Tadhg Furlong, 2 Rory Best (captain), 1 Cian Healy

Substitutes: 16 Sean Cronin, 17 David Kilcoyne, 18 Andrew Porter, 19 Tadgh Beirne, 20 Rhys Ruddock, 21 Luke McGrath, 22 Joey Carbery, 23 Jordan Larmour

Japan

15 Ryohei Yamanaka, 14 Kotaro Matsushima, 13 Timothy Lafaele, 12 Ryoto Nakamura, 11 William Tupou, 10 Yu Tamura, 9 Yutaka Nagare, 8 Amanaki Lelei Mafi, 7 Lappies Labuschagne (captain), 6 Kazuki Himeno, 5 James Moore, 4 Luke Thompson, 3 Koo Ji-won, 2 Shota Horie, 1 Keita Inagaki 

Substitutes: 16 Atsushi Sakate, 17 Isileli Nakajima, 18 Asaeli Ai Valu, 19 Wimpie van der Walt, 20 Michael Leitch, 21 Fumiaki Tanaka, 22 Rikiya Matsuda, 23 Lomano Lava Lemeki