DiPietro was coming off his first NHL victory on Friday, when he made 26 saves in a 4-2 win at the Anaheim Ducks.
Charlie McAvoy had four assists, and Pavel Zacha added two assists for the Bruins (8-2-1), who extended their point streak to seven games (6-0-1) in their return home following a 3-0-1 trip.
Since returning from a six-game suspension to begin the season for slashing Buffalo Sabres forward Zach Benson during Game 6 of the Eastern Conference First Round last season, McAvoy has six points (one goal, five assists) in five games.
Pastrnak has 14 points (six goals, eight assists) in his past seven games.
Justus Annunen made 25 saves in his first game of the season for the Predators (3-3-3), who have lost four of five (1-2-2).
Casey Mittelstadt gave the Bruins a 1-0 lead at 3:49 of the first period. Pastrnak avoided two defenders just inside the offensive blue line on the right side and fed Mittelstadt with a cross-ice pass before his wrist shot from the left face-off circle beat Annunen high stick side.
Elias Lindholm increased the lead to 2-0 with a power-play goal at 16:38. McAvoy sent the puck in from the blue line, and Lindholm redirected it over Annunen’s glove.
Pastrnak pushed it to 3-0 at 9:46 of the second period. He scored with a tip of McAvoy’s shot from above the right circle.
JJ Peterka made it 4-0 at 17:21, first redirecting Pastrnak’s centering pass off the left post, then poking in his own rebound.
Mark Kastelic’s goal on the backhand at 6:50 of the third period made it 5-0 before Pastrnak scored again at 15:00 for the 6-0 final, converting a wrist shot from the top of the slot.
