"It was a strong display. Sam (Warburton) said about it at half time and in the build up to the game - he was very, very vocal about a big goal being not to concede any tries," said Edwards.
"I was quite surprised when Argentina started going for goal when we were 20 points up. I suppose that was a complement to our defence.
"If I'm honest, I was very pleased with the defence last week (against South Africa), to concede 17 legal points against the Springboks - unfortunately we didn't go to the video referee for their third try."
Edwards wants an equally assured showing in what he expects will be another tough day defensively when the Tongans arrive in the capital this week, with the South Sea Islanders' abilities to attack from anywhere posing a substantial threat.
That free-flowing mindset will mean Wales cannot afford to switch off at any point during the 80 minutes, no matter where they are on the field.
And given that this week is an even shorter turnaround between games two and three of the four autumn Tests, Edwards says a heavy emphasis will be placed on ensuring everyone knows their own roles come kick off.
"We haven't got that long to prepare for Tonga, we've probably got one full training day and the captain's run. Hopefully, the work we've done over the last three weeks will mean our ruck defence system and all that type of thing will be second nature for the guys and, whatever team Warren decides to pick, the guys will know their roles," added Edwards.
"There are certain positions that we will have to do quite a lot of work with on the computers because physically you can't do that much work in four days. It's important that they know their roles and they execute them when it matters.
"Tonga are a very much about offloading and reacting to any turnovers they get. That's often the sort of defence you have to really concentrate on in the autumn series as opposed to the Six Nations as a lot of tries are scored from turnovers."