Mike Phillips, George North, Toby Faletau and replacement Ken Owens all scored against the Pumas as Wales bounced back from their opening defeat to South Africa to record their first autumn win since 2009.
"I was in a positive mood last week, I thought we played really well against South Africa," said Edwards.
"It was a real tough Test match and it showed the standard of rugby we were playing. I remember saying after the game that if we continue in this vein, good times are ahead and a week later we beat Argentina by a record score.
"I think the momentum is building and hopefully we can keep that going against Tonga on Friday. Hopefully we'll get a lot of people coming down to watch us play and we can reward them with some attacking rugby and some solid defence."
Saturday's clash with Argentina saw Wales add to their injury list. Debutant Cory Allen and Scott Williams became the latest centres to encounter problems. Wales are already without Jonathan Davies and Adam Jones after they were forced off against the Springboks while Jamie Roberts and Alex Cuthbert were ruled out before the start of the autumn series.
"Cory has dislocated his shoulder so he's going to be out for a while but Scott Williams is going to be assessed as the week goes on, he's got a toe injury which he battled on bravely with," said Edwards.
"It's good news on Owen Williams, he's fit and ready for selection. We'll have to see what side Warren goes for but you would expect some changes, it's important we develop some players for the future - we can't just have a first XV.
"Tonga do have specific offloading skills, there's no doubt about that. I've watched them against France and they play with a lot of width, they're pretty well coached and we do have to expect the unexpected at times.
"But they do have structure and they don't just make it up as they go along - they do have a plan."