Argentina (23) 63
Argentina ran in nine tries against minnows Namibia
Tries: Albacete, Leguizamon (2), M Contepomi, F Contepomi, Tiesi, Corleto, Penalty, Todeschini
Cons: F Contepomi (4), Todeschini
Pens: F Contepomi (2)
Namibia (3) 3
Argentina powered to a bonus-point win over Namibia in Marseille to keep alive their hopes of topping Pool D.
The Pumas started slowly but Patricio Albacete, Juan Manuel Leguizamon and Manuel Contepomi scored in the first half to quell the eager Namibians.
Felipe Contepomi added a fourth soon after the break and the floodgates opened as Argentina's flowing 15-man rugby proved too much for Namibia.
The Pumas will win the group with a bonus point against Ireland on Sunday.
Ireland, meanwhile, must beat Argentina by more than seven points and score a bonus point to progress, a result which would also see France top the group if they score a bonus-point victory over Georgia.
"It was important to get a bonus. We're still out there and next week against Ireland will be tough," said Pumas skipper Agustin Pichot.
"Namibia were always going to give their best - that's rugby, that's good. We worked hard and we kept our composure and we finished well."
The winners of Pool D will meet the runners-up from Pool C - likely to be Scotland or Italy - in Paris on 7 October, with the runners-up playing the likely group C winners New Zealand in Cardiff on 6 October.
Amid a carnival atmosphere in the Stade Velodrome in Marseille, the spirited Namibians took an early lead with a Morne Schreuder penalty but Argentina drew level through Felipe Contepomi after nine minutes.
The attritional opening stalemate, in which Namibia more than held their own, looked to have been punctured after a period of mounting Argentine dominance.
The Pumas recycled from a close-range maul and Felipe Contepomi slid through a grubber kick for his brother Manuel to chase, but his sibling was unable to control the ball in the grounding and Namibia were let off the hook.
Felipe Contepomi slotted another three-pointer shortly after and then Argentina's pressure paid off when lock Albacete claimed the try from a pile-up on the Namibia line.
Ten minutes later, Namibia's resistance showed the first signs of terminal decline when Argentine number eight Leguizamon picked up from the base of a scrum and muscled his way over on the blind-side.
They played very professionally against us, but it was too far for us
Namibia coach Hakkies Husselman
Argentina were swaying to their building rhythm and Manuel Contepomi got on the scoresheet when he capped a sweeping move into the left corner for a convincing lead at the interval.
The Pumas should have claimed their bonus point for four tries not long after the break but full-back Ignacio Corleto flung a wild pass into the stands with the touchline gaping.
But Felipe Contepomi made amends when he slipped through a hole in the Namibian defence minutes later to score under the posts.
That was that as a contest, and Argentina ran in five more tries through Leguizamon, Gonzalo Tiesi, Corleto, substitute Federico Todeschini and a penalty try to serve further notice that they are a growing force at this World Cup.
Nambibian coach Hakkies Husselman admitted it was a step too far for his mainly part-time side.
"They played very professionally against us, but it was too far for us," said Husselman, who at 34 is the youngest coach at the World Cup.
Husselman, who played at the last World Cup for Namibia, said that beating Georgia in their final group match is their goal.
"We really want to win that game," he added.
Argentina: Corleto; Senillosa, Tiesi, M Contepomi, Agulla; F Contepomi, Pichot (capt); Leguizamon, JM Fernandez Lobbe, Ostiglia, Albacete, CI Fernandez Lobbe, Hasan, Alberto Basualdo, Rodrigo Roncero.
Replacements: Ledesma, Scelzo, Kairelis, Longo, Miranda, Todeschini, Miras.
Namibia: Bock; Mouton, Grobler, Powell (capt), Africa; Losper, Jantjies; Redelinghuys, Meyer, Visser, Kazombiaze, Esterhuize, MacKenzie, Burger, Du Plessis.
Replacements: Horn, Lensing, Lindvelt, Senekal, van Tonder, Schreuder, Van Zyl