DURBAN, South Africa (AP) -- Argentina beat South Africa for the first time in a test on Saturday, with the 37-25 result in the final round of the Rugby Championship pushing the No. 2-ranked Springboks' World Cup plans toward turmoil.
Argentina scored four tries at Kings Park, three in the first half, and led 34-13 when wing Juan Imhoff completed his hat trick early in the second half, stunning the South African crowd.
It was only Argentina's second win in four seasons in the southern hemisphere championship, and while it gave the Pumas a huge boost in their own World Cup buildup, it was a third straight loss for South Africa.
Center Marcelo Bosch scored Argentina's other try, just two minutes in, and the Springboks struggled from then, trailing the whole game to lose to Argentina for the first time in 20 tests since 1993.
It left South Africa last in the Rugby Championship, the first time since 2012 and the introduction of the South Americans that the bottom team has not been Argentina.
Argentina carved South Africa open in the second minute, with flyhalf Juan Martin Hernandez and Imhoff combining in a set move off a lineout, and Imhoff sending center Marcelo Bosch clear to score.
Argentina was bossing South Africa's scrum as well, winning feeds against the head and penalties as they put the Springboks front row -- and the whole team -- under pressure.
Their backs were causing huge problems, too, with scrumhalf Tomas Cubelli skipping through a couple of missed tackles to set up Imhoff for his first try in the 23rd.
The Springboks were pulled together for a stern team talk by returning captain Jean de Villiers midway through the half. It didn't work.
Imhoff scored his second off a simple blindside move from a scrum in the 31st to take Argentina out to 21-6.
Lock Lood de Jager responded for South Africa, reaching out to score their first try after being driven to the line by his fellow forwards. That set off fireworks at Kings Park, but Argentina was the team doing all the celebrating.
In a half full of mistakes from South Africa, the home team gave away a penalty straight from the kickoff after that try and Hernandez nailed it for a 27-13 halftime lead.
Imhoff's hat-trick try three minutes into the second half was contentious. With play stopped for an Argentina penalty, and medics on the field, Argentina took a quick tap and Imhoff was completely free on the left wing to stretch the lead to 21 points.
Fullback Willie le Roux suggested a Springboks comeback when he motored down the right touchline for South Africa's second try in the 49th.
But Argentina weathered the Springboks' surge easily, with Bosch capping the Pumas' historic win with a dropped goal in the 63rd.
Even with 17 minutes still to play, South Africa could only come up with a last-minute try from Bryan Habana.