Griquas seemed to have the match in the bag when they led 23-6 after 50 minutes, but a dazzling comeback by the Pampas XV closed the gap to 23-18 before the home side tightened up, used their forwards to regain control and ended the match the stronger side.
The Argentineans did not help their cause by conceding a flood of penalties at the breakdown, allowing sharpshooter Vogt to kick seven of them, and their adventurous style of play was not helped by some dreadfully poor passing in the first half.
Griquas were happy to grind out the victory in the knockout match, using their hardworking forwards, who were an exceptionally well-knit unit.
The Pampas XV were obviously keen to keep ball in hand and, after Vogt and flyhalf Benjamin Madero traded penalties, it got them into trouble as Griquas eighthman Leon Karemaker forced them back over their own tryline to concede a five-metre scrum.
The Griquas scrum was rock-solid all game and, from that wonderful platform, flank Marnus Schoeman tried to go straight over the ruck to score. He was initially repelled, but then showed great strength to carry the ball wide and pass to lock Ligtoring Landman, who lived up to his name by dotting the ball down from some distance away.
Vogt missed the conversion, but the Griquas scrum continued to dismantle the famous Pampas set-piece, the disrepect reaching a peak when they nabbed a tighthead in the 14th minute, leading to an offsides penalty, which Vogt slotted from just inside his own half and from quite an angle (11-3).
The Pampas XV then put their counter-attacking approach to good use when wing Facundo Barrea and scrumhalf Martin Landajo burst into Griquas territory and won a penalty, which Madero kicked (11-6).
Griquas were happy to keep the ball among their forwards for the rest of the half, their pick-and-goes, wonderful rolling maul and powerful scrumming earning Vogt two more penalties (17-6) before half-time.
Two more Vogt penalties early in the second half, the first after a wonderfully precise and penetrative rolling maul, pointed to normal service being resumed after the break.
At 6-23 down, the Pampas perhaps had good reason to stick with their attacking approach and wing Manuel Montero burst clear at the back of a lineout before his chip-and-gather created the space for outside centre Gabriel Ascarate to score at the corner flag.
The try of the match followed on the hour mark as most of the Pampas team handled the ball from the kickoff, the handling and support play all coming together as Madero scored after the home side eventually ran out of defenders. The flyhalf’s conversion was good and the visitors had closed the gap to just five points.
Much of the pressure Griquas were under was a result of their own mistakes and they tightened up again significantly in the last quarter to seal the win.
Good driving play and ball-retention, followed by a swift attack down the left, resulted in a penalty, successfully converted by Vogt (26-18), but the fullback did miss a third shot at goal with three minutes remaining.
It did not matter though and the defending champions were left to rue their lack of technical precision and structure. The Pampas XV had played the more exciting rugby, but the more structured Griquas team were able to feed off their mistakes, always a crucial factor in knockout rugby.
Griquas, with an experienced tight five and highly capable loose trio, are not going to be easy to beat at home, which is where they will keep playing by virtue of them topping the North Section log.
The Pampas XV, although they had 12 of last year’s title-winning side back, have not been the same team as in 2011 and, for the sake of their Rugby Championship hopes, hopefully they will have better players in Argentina.
Griquas will now face the winners of the match between the Sharks XV and the Blue Bulls in Durban on Saturday in the semifinals.