Argentina down Japan in Nantes thriller to reach World Cup last eight
Argentina's Santiago Chocobares scored a try after 67 seconds but that served only as an appetiser for a thrilling contest between two well-matched teams playing for the right to take on Wales in the last eight in Marseille next Saturday.
Emiliano Boffelli also crossed for a try and contributed nine points from the kicking tee for Argentina as the twice World Cup semi-finalists returned to the knockout stages after missing out in 2019.
"It's been so competitive, everyone's fighting for their lives," said a relieved Pumas coach Michael Cheika.
"We gave them a few easy entries back into the game but you look on the positive and if we can turn that around next week, maybe we'll be a chance."
Japan, whose run to the quarter-finals on home soil four years ago captured the hearts of a nation, head home despite a battling performance and tries from lock Amato Fakatava, scrumhalf Naoto Saito and replacement winger Jone Naikabula.
"I guess as a coach you can't ask for much more," said Jamie Joseph, whose seven-year reign as Japan coach ended with the defeat.
"My boys gave everything, they are behind me breaking down crying. We conceded some soft tries, that's the hurting part, but it will go away with time."
The Pumas made the perfect start, driving a maul up the middle of the pitch before releasing the ball to Chocobares, who skipped through the defensive line and rounded the last defender to touch down.
Japan hit back 14 minutes later in unlikely fashion when lock Fakatava put up a speculative chip kick on the wing and showed a great turn of pace to regather it and trundle over the line for a score.
Brave Blossoms flanker Pieter Labuschagne, who missed the World Cup opener after being shown a red card against Fiji in August, was again penalised for a high hit in the 23rd minute and sent to the sin bin.
The Pumas hit the front again just before the half-hour mark when scrumhalf Gonzalo Bertranou carved through the Japan defence and drifted across the pitch to find winger Carreras running a great line in support on the left wing.
Boffelli extended the lead to 15-7 with a penalty before Labuschagne returned but it was Japan who went into the break with the momentum after Saito crossed in the 38th minute to make it a one-point game.
Centre Dylan Riley started the move in midfield before releasing Siosaia Fifita, who left Boffelli floundering with a sidestep before finding his scrumhalf to supply the finish.
Argentina returned to the direct approach early in the second half and got their reward within six minutes when forward pressure created space on the outside for Carreras to grab his second.
A Rikiya Matsuda penalty and a 40-metre drop goal from Lomano Lemeki cut Argentina's lead to 22-20 before another classy backline move from the Pumas put Boffelli over in the corner with 20 minutes to play.
The Brave Blossoms again hit back through Naikabula but Carreras soon carved his way through the Japanese defence to complete his hat-trick and give Argentina a nine-point cushion going into the last 10 minutes.
Replacement flyhalf Nicolas Sanchez, playing his 101st test, extended the cushion with a penalty five minutes from time and the Argentines held firm to progress with pool winners England.