Japan shocked the globe for the second time in four years by stunning Ireland 19-12 to light a bomb under Pool A and a fire under their home World Cup.
Japan 19-12 Ireland
Japan tries: Fukuoka
Japan conversions: Tamura
Japan pens: Tamura 4
Ireland tries: Ringrose, R Kearney
Ireland conversions: Carty
Match highlights
Match report
Japan shocked the globe for the second time in four years by stunning Ireland 19-12 to light a bomb under Pool A and a fire under their home World Cup.
The Brave Blossoms tore through Ireland time and time again in Shizuoka, triumphing through superior tenacity and supreme intensity.
The world's 10th-ranked team beat the second-best outfit, who entered this tournament ranked number one in the standings.
Wing Kenki Fukuoka ran in the try that sealed Japan's famous victory, immediately invoking memories of their breathless 34-32 win over South Africa in Brighton in 2015.
Fukuoka was not even meant to be in the match squad, but stepped onto the bench when William Tupou picked up a late injury and Lomano Lemeki started.
The 27-year-old stormed in at the corner to send the Shizuoka Stadium Ecopa into delirium though, and rip up the pre-written expectations for Pool A.
Ireland failed to cope with Japan's intensity and precision, and this defeat leaves their group wide open.
Joe Schmidt's men would have expected to move from their potent 27-3 win over Scotland and press through to top Pool A for a quarter-final against South Africa.
If Japan could repeat this level of performance however, it could be the Brave Blossoms who top the pool, with the hosts having already bested Russia 30-10.
That would leave Ireland and Scotland scrapping it out for second place, and a possible quarter-final against back-to-back world champions New Zealand.
Garry Ringrose and Rob Kearney bagged early tries as Ireland's clear plan to expose Japan's failings under the high ball paid good dividend.
Jack Carty had a fine first-half in deputising for Johnny Sexton on just his second Test start.
But Japan refused to let Ireland gain any control through the dominance of possession, and the hosts' relentless pace caught boss Schmidt's men off guard.
Japan will move on to face Samoa in Toyota on Saturday, with a brittle Scotland doubtless now very nervous about taking on the tournament hosts in Yokohama on Sunday, October 13.
Ireland meanwhile will take on Russia in Kobe on Thursday, with much wound-licking to come between now and then.
Tamura missed a regulation shot at goal as Japan opened the clash at a furious pace.
Once Ireland settled, Schmidt's men set up Japan perfectly for Carty to bag full reward from a crossfield punt.
Ringrose comfortably beat Lemeki to the high ball, fielding cleanly and finishing in style.
Tamura's first penalty had Japan on the board after Peter O'Mahony was ruled offside at a ruck.
But Ireland bulldozed the Japan scrum, punted the penalty upfield for a good platform - and Carty again outfoxed the home defence with his kicking game.
The 27-year-old chipped over the line, tapped back - and full-back Kearney scooped up to barrel home for the try.
🇯🇵 Hosts Japan cause a huge Rugby World Cup shock by beating Ireland 19-12!
— Sporting Life (@SportingLife) September 28, 2019
🏉 Japan's Timothy Lafaele was one of the stars of the show...
#JPNvIRE #RWC2019 pic.twitter.com/R073J5bFgu
A lost lineout put Ireland under huge pressure as Japan continued to race forward at a hectic pace. Conor Murray was pinged for killing the ball in his own 22, so Tamura posted the facile penalty to cut Ireland's lead to 12-6.
Another Tamura penalty allowed Japan to cut Ireland's lead to just three points.
And Ireland were so rattled by the Japanese onslaught that Carty sent the restart dead, handing the hosts a scrum on the halfway line.
Japan stole the chance for one last attack in the half, ploughing through 16 phases with time well and truly up.
But just when the hosts looked to have broken Ireland's defence, hooker Shota Horie's grubber kick evaded the onrushing Lomano Lemeki - and Ireland tiptoed to half-time with that slender 12-9 lead.
Japan continued to threaten, until Ireland won a scrum penalty and kicked to the corner rather than for goal. Ireland duly lost the lineout however, wasting the hard-won platform.
Japan kept on coming, time and again, and eventually Fukuoka crossed in the left corner.
CJ Stander collided with Chris Farrell in a bungled break from a scrum, gifting Japan the scrum deep in the Ireland 22.
The pumped-up hosts lapped up the chance, powering through the middle before whipping the ball wide.
Tamura's fine conversion then put Japan into a 16-12 lead on the hour.
Ireland emptied the bench and pressed for a score to turn the tide, but it never came.
And when Tamura posted his fourth penalty for a 19-12 lead, Japan's stunning victory was complete.
Match reaction
Jamie Joseph revealed Japan spent three years plotting their stunning 19-12 dismantling of Ireland in Shizuoka.
The Brave Blossoms boss hailed one of the World Cup's greatest ever upsets by insisting it was a triumphant gameplan painstakingly distilled and refined.
Japan's Kiwi boss claimed Ireland, in contrast, had only been working on this match for one week and paid the price.
Former Highlanders boss Joseph insisted Ireland had not disrespected Japan, but was adamant that disparity in preparation had proved pivotal.
"There was a lot of relief around what we were able to do," said Joseph.
"We have been preparing for this game for a hell of a lot longer than the Irish have.
"We've been focusing on today for the last year at least, and probably subconsciously the last three years.
"And Ireland have been thinking about it since Monday. So we just felt we had to execute our plan."
Asked if Ireland's limited direct preparation to face Japan showed a lack of respect, Joseph replied: "Not at all, they are a great rugby team, they played last week and have had a shorter turnaround.
"They've played a lot of Test matches recently, they are professional athletes.
"Our preparation window for the World Cup has been a little different, we've been training a hell of a lot."
Japan set their home World Cup alight by dumping Ireland on their backsides in serious style at the Shizuoka Stadium Ecopa.
Joseph's men blitzed Ireland in all areas, recovering from a 12-3 deficit to storm to a victory that left the raucous home crowd in raptures.
This was a triumph every inch as impressive as Japan's last-gasp 34-32 victory over South Africa in Brighton at the last World Cup in 2015.
Wing Kenki Fukuoka sealed the result, haring into the left corner to leave Ireland outgunned and outplayed, with early tries for Garry Ringrose and Rob Kearney mere footnotes on the scoring charts.
Hooker Shota Horie led from the front in an all-court performance for the hosts, leaving Joseph purring at his continually developing game.
"He's a quality rugby player and this year he's been in great form," said Joseph.
"Physically, set-piece, it's something that wasn't high on his priority list.
"He was renowned for his skill-set but now he can do both loose work and tight.
"He can throw out the back passes, he can jackal like a flanker but he can also scrummage powerfully and put in little kicks and things like that.
"I think he's the ultimate tight forward, and he's a big reason why we performed tonight."
Ireland boss Schmidt was left to praise the winners and admit his side must now tend their sizeable wounds.
"I'd like to first of all congratulate the Japanese team for the energy, the intensity, the skill they brought to the game tonight," said Schmidt.
"They are a big team, they played big and they were very difficult to contain.
"I felt we probably controlled the first quarter reasonably well, to go 12-3 up with two tries scored.
"It's probably exactly what we'd asked for, but the longer the game went the more oxygen they got from penalties and from the skill that they showed and you've got to commend them for that. It's not the first time we've seen them do it, it's not a surprise to us that they were incredibly tough to beat.
"The quality even of Michael Leitch coming off the bench - I thought he really added value.
"Yu Tamura and (Timothy) Lafaele, I thought they got a bit of an armchair ride. We got penalised for a few offsides and then we became hesitant.
"Once we became hesitant we couldn't really put the same pressure on them as they were putting on us - and they got a real roll on."More Rugby World Cup content
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