Smit celebrated his 50th match as Springbok captain in a Test match that was made even more noteworthy as De Villiers' first in charge since his appointment in January.
The 51-year-old, the first black coach to ever lead the Springboks, has a tough act to follow after his predecessor Jake White led the team to their second World Cup success in France last year.
To further add to the pressure on him, De Villiers' appointment was met with criticism in South Africa with many supporters unconvinced by his record.
While De Villiers had enjoyed success with the South Africa Emerging Team and the Under-21s many followers pointed to his lack of Super 14 experience as a cause for concern.
Victory against the reigning Six Nations champions may have provided the perfect icebreaker for De Villiers to win over public support, however Smit revealed the coach had already won his vote of confidence.
"I had my reservations as well before I met Peter," Smit told Afrikaans Sunday newspaper Sondag.
"I met him the first time when he came to see me about being captain. It was a brave decision at the time and Peter has a determination to prove himself.
"He is still an unknown factor for a lot of people. We need to remember that we were used to Jake White's style of coaching for four years and we didn't really know what to expect from Peter.
"He didn't have a record in the Super 14 - like Jake - and was successful at under-21 level."
De Villiers had just over a week to work with the players before the first Test following the completion of the Super 14 season.
Despite that Smit believes the team had gelled well under the new management.
"We haven't had much time as a team but every day is getting better under Peter," Smit said.
"We get a lot more responsibility and anything that isn't for the good of the team, is thrown out. We are certainly not treated as children."
The Springboks will face Wales in the second Test in Pretoria on Saturday.