South Africa outplayed an under-strength Thailand team, who managed only a single shot on goal and were constantly stretched by the home team.
"There were a lot of positives to be taken from the game. I don't care about the quality of the opponent," Parreira said after the victory on Sunday.
"It's a big improvement. We are now in our final stages of preparation and we are looking for two things - performance and results. The result helps build confidence and as for the performance, the players look more comfortable on the ball.
"We still need more penetration but I feel it is coming," said Parreira, tasked with ensuring the World Cup hosts have a competitive team for the upcoming tournament.
South Africa have now gone eight matches unbeaten under Parreira since he returned to the job in November, albeit low key matches with his teams mainly made up of home-based players.
South Africa's foreign-based payers arrive this week to join preparations, which have already seen training camps in Brazil and Germany over the last two months.
"Now we have stronger opponents coming in our build-up. Every game will be tougher and will help us more," Parreira added.
Bafana Bafana's next match is against Bulgaria at Soccer City next Monday, followed by a match on May 27 against Colombia. Parreira said another fixture was set for May 31 but the opponent and venue yet to be determined.
South Africa's final tune up game is against Denmark in Pretoria on June 5.
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