Pirlo raised eyebrows after handing debuts to Weston McKennie and Dejan Kulusevski as Gianluca Frabotta fitted in for the injured Alex Sandro at fullback.
Cristiano Ronaldo brought Sampdoria goalkeeper Emil Audero to the evening's first save in the earlier exchanges as he got behind the defence following a through ball for a shot on target.
Juventus would break the deadlock on 13 minutes when Kulusevski curled into the bottom corner following a loose ball inside the area for a debut goal.
The Bianconeri managed to drop momentum following the half-hour mark and allowed the visitors a few openings as Federico Bonazzoli dragged wide of the mark from a promising area.
Ronaldo should've given Juventus a second eight minutes to halftime off an inviting opportunity from a loose ball in the area, but the Portuguese side-footed wide.
Three straight substitutions from the Blucerchiati at the interval saw Fabio Quagliarella, Gaston Ramirez and Maya Yoshida coming in.
Juventus however still had a chance to go two goals clear a little later after Frabotta ran onto a diagonal ball near the area before stinging the gloves of Audero.
The visitors began finding spaces in dangerously looking areas up front, as Ramirez followed by Morten Thorsby went off range towards the 60th minute while Ronaldo scuffed a clear opening.
The Old Lady made the points safe in the final 12 minutes after Leonardo Bonucci tucked home from an open goal following a loose ball off a corner.
Following end-to-end goalmouth action either end, Ronaldo finally got on target two minutes from time when he turned home Aaron Ramsey's pass to help his side to a fine start to the season.