Alberto Gilardino’s first-half goal gave Italy the lead in the World Cup qualifier in Palermo, but they had captain Buffon to thank for earning a vital three points as he pulled off several top-class saves as the visitors pressed hard for the equaliser after half-time.
Italy are now all but assured of reaching Brazil 2014 as the result leaves them seven points clear of Bulgaria at the summit of Group B, but coach Prandelli knows his side rode their luck at times on Friday.
"Gigi saved the result with an extraordinary performance, so it’s nice to suffer and still win," he told RAI Sport.
"Bulgaria poured forward towards the end, they gambled it all, so it was predictable we would suffer."
The former Fiorentina boss was forced into making several changes for the game, with Mario Balotelli, Pablo Daniel Osvaldo and Riccardo Montolivio all unavailable.
And Prandelli felt these alterations were partially responsible for his side’s stuttering performance.
"Unfortunately tonight we had to make three changes due to injuries so it became complicated," he added.
"Our fitness levels are not optimal and that makes it all much more difficult."
Italy now need only one win from their remaining three games to secure their place at next year's finals, and they have an opportunity to do so when they entertain the Czech Republic - who succumbed to a home defeat to Armenia - in Turin on Tuesday.
"We’ll try to get as many players as possible back to fitness," Prandelli added.
"The Czechs are also gambling their last chips, so I warn you it is not going to be a walk in the park, but we’ll give it our all too. We’re fired up."