The visitors were without several of their experienced names and scored nine tries against an injury-hit Italy as they made an emphatic start to their November fixtures.
Erasmus has gambled at times to bring through new players and grow his squad pool ahead of their 2027 Rugby World Cup defence and he is starting to see the fruits of that policy.
"I think the biggest thing is that we've been together for eight years now and we've slowly been bringing new people into the system,” Erasmus told reporters.
"Players like Ethan (Hooker), Sacha (Feinberg-Mngomezulu), Ruan (Nortje), Cameron (Hanekom), Jan-Hendrik (Wessels) and Paul de Villiers are among those who haven't been with us since 2018.
"The nice thing is that we've tried to bring people in here and there. Then, when you go into a game like this and pick a team that is match fit and ready, everybody is calm and understands the whole system.”
South Africa led 45-0 at halftime in a dominant opening 40 minutes but made numerous errors in the second period as some sloppiness crept in.
"We know it wasn't perfect. We have to play much better than this if we want to be competitive against France and Ireland (in the next two weeks). I think it's almost impossible to put together 80 minutes where you are at 100%.”
South Africa lost lock Salmaan Moerat ahead of the game when he pulled out with back spasms but Erasmus said there were no other injuries from the contest.
He also had praise for the discipline of his side, who conceded only five penalties all game.
"We're really trying hard to operate within the laws, especially when it comes to changes in tackle height and all the things they are focusing on at World Rugby,” he said.
"I don't think there were many penalties that were deliberate. There was one for not rolling away but there weren't a lot of silly or avoidable penalties. Those are the ones that hurt you and frustrate you.”