In a thrilling game Argentina and Scotland proved a good match, with each struggling to break the others defence.
After trading penalties and drop goals, the Scottish team were looking good for a win, as they lead the Argentinians with 12 points to six.
But with seven minutes to go a great individual try by Lucas Gonzalez Amorosino of Argentina, followed up by a superb conversion under pressure by Felipe Contepomi secured Argentina a win by just one point.
It was Argentina who knocked them out at the quarter-finals of the last World Cup, and Scotland coach Andy Robinson said the loss had hit his side hard.
This result means that both teams and England can still go through to the next round, though Scotland will need to beat England in their match to keep their hopes alive.
Elsewhere Ireland gave Russia a pummeling and by the end of the first half had a comfortable 36 – 0 lead.
But in the second half the Russians managed to find some faults in the Ireland defence and got back two tries of their own.
None-the-less Ireland still finished with a decisive win, with 62 points to 12 securing their place at the top of the table.
The much Hyped game between Fiji and Samoa turned out to be a dissapointment, with the only points from a scrappy first half coming from the boot of Samoan Tusi Pisi.
In the end it was Samoa who kept their slim hopes of a quarter final place alive and now sit in second place. However they have played one more game than third place Wales, who should win when they face Namibia on Monday.