The two teams meet in Marseille - kicking off a potentially absorbing weekend of World Cup knockout action - with both harbouring legitimate hopes of a place in the semis.
Wales have turned around their fortunes after a poor Six Nations campaign earlier this year - plus plenty of off-field drama over players' contracts - to finish top of their World Cup group, convincingly beating Australia 40-6 after holding out for a dramatic win over Fiji in their opening Pool C encounter.
Whether their tournament would have taken a different turn had Fiji not dropped the ball when they looked sure to secure a last-gasp victory in their meeting, remains a matter of conjecture.
But coach Warren Gatland is pleased with how his unbeaten side have built momentum over the last six weeks and topped their group.
"We haven't had the perfect performance yet, but we have shown that we are a hard team to beat," he said on Thursday.
"There is a lot more growth in this squad – collectively and individually – and we cannot wait to get out there in Marseille on Saturday."
Argentina will feel they, too, are capable of much more having scraped their way through to the last eight.
They are two-time semi-finalists – one less than Wales – but four years ago failed to advance past the group phase.
That also looked to be a possibility this time around after they lost to England in their opening Pool D match before overcoming Japan in a see-saw winner-takes-all clash last weekend.
"It's about understanding the body of work that's been going on for coming on two years since I've been with the team," said Pumas coach Michael Cheika on Thursday when pressed about a mediocre showing in France.
"All those things we've been working on in that time will give us that feeling of being ready for a game."
But knowing he needs more of spark in his side, Cheika has taken a gamble on the form of injury-plagued scrum-half Tomas Cubelli, while reshuffling his loose forward trio after Pablo Matera's tournament-ending injury.
Gatland has done the same with the Wales line-up after Taulupe Faletau broke his arm last week. But the Welsh have been significantly boosted by the return from a pectoral injury of fly-half Dan Biggar, who has been a past match-winner for his country.
Wales have won two previous World Cup meetings against Argentina and were also 20-13 winners when the two countries met in Cardiff last November.