The La Liga giants needed a brace from Lionel Messi in the final 18 minutes to come back after trailing during the Champions League clash at Camp Nou.
 
Vilanova said it was far from his team's most polished performance, but was glad they opened Group G with a win.
 
"The performance was good, but not the best. We played well, opening up the pitch," he said afterwards.
 
"The best thing was the reaction of the players. It's a good feeling because it's important to start with a win.
 
"They were difficult to unlock and made things hard for us with a couple of counter-attacks.
 
"We had a lot of chances. Teams only employ this kind of approach when they play us."
 
Barcelona felt the absence of Gerard Pique, who was substituted after 12 minutes because of a foot injury, and Vilanova said youngsters would be used – if needed – to fill the void left by the defender.
 
Spartak Moscow coach Unai Emery, meanwhile, said his team were unable to produce the 'perfect' performance needed to beat Barcelona.
 
"We got 50 percent of what we wanted. I have the misfortune of being in a group of coaches who have never won at the Camp Nou," the former Valencia boss said.
 
"The most important thing was to score goals, which we did, but it was not enough. In attack we wanted something more. To beat Barcelona you need to play a perfect match."
 
Emery's side troubled Barcelona on the counter-attack throughout the clash and led 2-1 when Romulo struck on the hour-mark.
 
But Messi put away a Cristian Tello pass and then headed in an Alexis Sanchez cross as Barca took all three points.
 
"You can stop Messi for a certain amount of time, but when you concentrate on him other players find space so it is very difficult," Emery said.
 
"Overall the match was great and I am happy with our display, if not the result."