However, Townsend admitted that Pool A rivals Japan and Ireland were favourites to secure last-eight positions and stressed the need for two more bonus-point wins.
"That was a true reflection of who we are and what we are capable of and what playing for Scotland means to the players," said Townsend, in reference to last weekend's woeful 27-3 loss to Ireland.
"To win and play better was the target and anything extra would be an exceptional performance, and it was, especially in the first half," the former Scotland fly-half told reporters.
The coach took responsibility for not preparing the team to start well against Ireland but said that defeat "didn't make us a bad team."
Scotland kicked off in Kobe knowing anything other than a bonus-point win would likely spell the end of their hopes of reaching the last eight from a tightly-contested Pool A.
But against Samoa they were 20-0 ahead at half-time after a burst of 17 points in eight minutes, with wing Sean Maitland and Greig Laidlaw scoring converted tries.
Fullback Stuart Hogg then kicked an outrageous drop goal from some 50 metres and a pair of penalty tries after the break completed the victory - although the bonus point came only five minutes from time.
Both sides struggled to maintain possession in what Scotland captain Stuart McInally described as "tough", humid conditions under the closed roof at the Kobe Misaki Stadium.
"With the roof closed, I was sweating at the start of the warm-up," said the hooker.
"The ball was slippy but it was the same for both teams so it was pleasing we managed to force a few errors from Samoa because of our pressure."
Scotland, Samoa and Ireland all have one win from two games, while tournament hosts Japan are in pole position following wins over Russia and the Irish.
- 'Japan and Ireland favourites' -
"We are still in the tournament," said Townsend.
"The bonus point gives us an opportunity to go to our next game (against Russia on October 9) and get maximum points again.
"If we do, it will be a game against Japan (on October 13, just four days after the Russia match) to go into the quarter-finals.
"Japan and Ireland are still favourites to get out of the pool. We have to win our next two games and get at least one bonus, potentially two."
Asked whether he approved of bonus points as a potential method of deciding quarter-final qualification, Townsend replied: "I think my answer would be biased towards whatever works in our favour.
"We knew the rules coming in. The challenge is there. If it means having to score four tries and deny Japan a bonus point then it is an even bigger challenge."
Monday's result was all the more enjoyable for Townsend as it was the first time in his 29 Tests in charge that Scotland had 'nilled' an opponent.
"That's a real credit to the players and to Matt Taylor, our defence coach, who does a fantastic job," said Townsend.
"Tonight they defended with passion. They got off the line and put big hits on big men and did it time and time again."