Glasgow ace Rob Harley's stoppage-time try was converted by Greig Laidlaw to seal a last-gasp victory in Apia after the Scots had previously seen off both Australia and Fiji.
Evans, who was a second-half replacement for the Scots' other try- scorer Joe Ansbro, has no doubt about the importance of the unbeaten Southern Hemisphere tour.
He said: "There was extra importance attached to this tour because of how badly the Six Nations went. There is no doubt about that.
"But to have become the first Scotland team to come back from a Southern Hemsiphere tour of Australia, Fiji and Samoa with three wins is massive.
"I think the way we kept going until the end and came up with the goods shows the squad strength of character.
"What we have got to make sure is that we build on this in the autumn Test series with New Zealand, South Africa and Tonga."
Evans was delighted for his former Glasgow team-mate Harley whose late try was crucial in claiming the win. The Scotland star said: "For Rob to earn his debut and then round it off with the try that helps us win the Test was just fantastic.
"That will give him a huge amount of confidence when he goes back to Glasgow.
"But you look at Ryan Grant, the Glasgow front row. He has come here uncapped and now played every minute of all three Tests and experienced being part of a winning Scotland team.
"Then you have Tim Visser getting his first caps. So there are many positives. But we have to make sure we use it as a real launchpad."
Scotland head coach Andy Robinson believes the tour has given his side the platform they need to confront the daunting autumn Test series.
He said: "I'm really delighted with what we have achieved on this trip. The boys put in three big shifts in incredible conditions.
"New Zealand will be a real challenge, especially when you remember two years ago they defeated us 49-3 at Murrayfield.
"But if we want to be successful we have to push the boundaries and play against the best teams.
"We've got South Africa as our second game in the autumn and we will have to stand toe-to-toe with them.
"Then it's Tonga and we know they have improved as a team."