Mateo Carreras scored a hat-trick of tries as Argentina beat Japan 39-27 in a thriller in Nantes on Sunday to set up a World Cup quarter-final against Wales.
Los Pumas finished as Pool D runners-up behind England and fixed a date against the Welsh in Marseille next weekend. Defeat meant Japan failed to advance to the knock-out phase.
"We like to be a fighting team and we fight for everything, but the resilience of this team is what makes the difference here. I am really proud of the team on how we fought," said Argentina captain Julian Montoya.
"We want to win every game, we started the game with England not the way we wanted to and we were upset with our performance," he added in reference to an opening pool 27-10 loss to the English followed up by victories over Samoa (19-10) and Chile (59-5).
Montoya's counterpart Kazuki Himeno said he was "really disappointed" with the result.
"We talked about climbing Mount Everest, we didn't get to the summit and have the Cherry Blossoms at the top. However, our legacy and the culture of Japanese rugby will continue and believe we will improve from now on."
In a roller-coaster of a game at the Stade de la Beaujoire in glorious, sunny conditions, both sides threw caution to the wind, Argentina eventually outscoring the Brave Blossoms by five tries to three.
The Pumas made a sensational start, Marcos Kremer pounding Himeno from the kick-off and then producing a driving maul before the ball was recycled right into the hands of Santiago Chocobares.
The Toulouse centre broke a tackle in midfield and sidestepped full-back Lomano Lemeki for a brilliant try with barely two minutes gone. Emiliano Boffelli hit the extras.
On the back of a scrum penalty, Japan surged into Argentinian territory. Naoto Saito's dink over the top was gathered by Lemeki and worked right where Michael Leitch did well to hold on to a bobbling ball.
- Fakatava's try of the tournament -
Argentina cleared their lines, but what came next was superb. Japan moved the ball quickly to the left, where Leitch drew two defenders and offloaded to hard-charging lock Amato Fakatava.
Fakatava accelerated past the first defender, ball in one outstretched hand, and then chipped ahead.
The ball sat up nicely and the Tongan-born lock gathered and galloped over for a fine individual try converted by Rikiya Matsuda.
Japan were hit by a 22nd-minute yellow card for flanker Pieter Labuschagne for a high tackle on Pumas prop Thomas Gallo, but Boffelli pushed the penalty wide.
Argentina, however, scored their second just minutes after, Juan Cruz Mallia jumping high to field a soaring Kotaro Matushima up-and-under.
Mallia split the defence and offloaded to scrum-half Gonzalo Bertranou, who went on a rampaging run left and, with right winger Matsushima out of position, found Mateo Carreras to step around Lemeki for a straight run in to the line.
Boffelli missed the conversion, but hit a penalty to take Los Pumas out to 15-7.
Japan raced back, slightly against the run of play. Siosaia Fifita broke before finding Saito on his inside for another beauty of a try, Matsuda converting to make it a one-point game at half-time.
Argentina drew first blood in the second period as Carreras grabbed his second try after good work by Chocobares. Boffelli converted.
Matsuda pulled back a penalty for Japan and Lemeki struck a long-range drop-goal in a gripping contest that neither side could run away with.
Argentina hit back with another well-worked try, Boffelli crossing in the corner. He then converted to make it 29-20 going into the last quarter.
With that deficit in mind, Matsuda spurned a pot at goal to kick for the corner.
After multiple phases and a penalty, Saito worked the ball right and Jone Naikabula crashed , Matsuda converting to ensure a nerve-racking final 10 minutes.
Any Argentinian anxiety was allayed as Carreras skipped through a tiring defence for his third try, under the posts.
Nicholas Sanchez converted and added a late penalty to set up a mouth-watering last-eight clash with Wales.
lp/pb
